///////////////////////////////////////////////////////////////////////////////
// Name:        wx/strvararg.h
// Purpose:     macros for implementing type-safe vararg passing of strings
// Author:      Vaclav Slavik
// Created:     2007-02-19
// Copyright:   (c) 2007 REA Elektronik GmbH
// Licence:     wxWindows licence
///////////////////////////////////////////////////////////////////////////////

/*
    This header contains helpers for implementing printf-like functions in
    wxWidgets as well as legacy WX_DEFINE_VARARG_FUNC macros that are not used
    by wxWidgets itself any more, but are preserved here as they can be used in
    the application code (even if they had never been part of documented API).

    The only non-deprecated parts of this header are wxFormatString class and
    wxFormatStringSpecifier and wxArgNormalizer templates, which are used by
    wxWidgets itself.
 */

#ifndef _WX_STRVARARG_H_
#define _WX_STRVARARG_H_

#include "wx/platform.h"

#include "wx/cpp.h"
#include "wx/chartype.h"
#include "wx/strconv.h"
#include "wx/buffer.h"
#include "wx/unichar.h"

#include <string>
#include <type_traits>
#include <vector>

#ifdef __cpp_lib_string_view
    #include <string_view>
#endif // __cpp_lib_string_view

class WXDLLIMPEXP_FWD_BASE wxCStrData;
class WXDLLIMPEXP_FWD_BASE wxString;

// There are a lot of structs with intentionally private ctors in this file,
// suppress gcc warnings about this.
wxGCC_WARNING_SUPPRESS(ctor-dtor-privacy)

// ----------------------------------------------------------------------------
// WX_DEFINE_VARARG_FUNC* macros
// ----------------------------------------------------------------------------

// This macro is used to implement type-safe wrappers for variadic functions
// that accept strings as arguments. This makes it possible to pass char*,
// wchar_t* or even wxString (as opposed to having to use wxString::c_str())
// to e.g. wxPrintf().
//
// This is done by defining a set of N template function taking 1..N arguments
// (currently, N is set to 30 in this header). These functions are just thin
// wrappers around another variadic function ('impl' or 'implUtf8' arguments,
// see below) and the only thing the wrapper does is that it normalizes the
// arguments passed in so that they are of the type expected by variadic
// functions taking string arguments, i.e., char* or wchar_t*, depending on the
// build:
//   * char* with UTF-8 encoding if wxUSE_UNICODE_UTF8 and the app is running
//     under an UTF-8 locale
//   * wchar_t* if wxUSE_UNICODE_WCHAR or if wxUSE_UNICODE_UTF8 and the current
//     locale is not UTF-8
//
// Note that wxFormatString *must* be used for the format parameter of these
// functions, otherwise the implementation won't work correctly. Furthermore,
// it must be passed by value, not reference, because it's modified by the
// vararg templates internally.
//
// Parameters:
// [ there are examples in square brackets showing values of the parameters
//   for the wxFprintf() wrapper for fprintf() function with the following
//   prototype:
//   int wxFprintf(FILE *stream, const wxString& format, ...); ]
//
//        rettype   Functions' return type  [int]
//        name      Name of the function  [fprintf]
//        numfixed  The number of leading "fixed" (i.e., not variadic)
//                  arguments of the function (e.g. "stream" and "format"
//                  arguments of fprintf()); their type is _not_ converted
//                  using wxArgNormalizer<T>, unlike the rest of
//                  the function's arguments  [2]
//        fixed     List of types of the leading "fixed" arguments, in
//                  parentheses  [(FILE*,const wxString&)]
//        impl      Name of the variadic function that implements 'name' for
//                  the native strings representation (wchar_t* if
//                  wxUSE_UNICODE_WCHAR or wxUSE_UNICODE_UTF8 when running under
//                  non-UTF8 locale, char* otherwise)  [wxCrt_Fprintf]
//        implUtf8  Like 'impl', but for the UTF-8 char* version to be used
//                  if wxUSE_UNICODE_UTF8 and running under UTF-8 locale
//                  (ignored otherwise)  [fprintf]
//
#define WX_DEFINE_VARARG_FUNC(rettype, name, numfixed, fixed, impl, implUtf8) \
    _WX_VARARG_DEFINE_FUNC_N0(rettype, name, impl, implUtf8, numfixed, fixed) \
    WX_DEFINE_VARARG_FUNC_SANS_N0(rettype, name, numfixed, fixed, impl, implUtf8)

// ditto, but without the version with 0 template/vararg arguments
#define WX_DEFINE_VARARG_FUNC_SANS_N0(rettype, name,                          \
                                       numfixed, fixed, impl, implUtf8)       \
    _WX_VARARG_ITER(_WX_VARARG_MAX_ARGS,                                      \
                    _WX_VARARG_DEFINE_FUNC,                                   \
                    rettype, name, impl, implUtf8, numfixed, fixed)

// Like WX_DEFINE_VARARG_FUNC, but for variadic functions that don't return
// a value.
#define WX_DEFINE_VARARG_FUNC_VOID(name, numfixed, fixed, impl, implUtf8)     \
    _WX_VARARG_DEFINE_FUNC_VOID_N0(name, impl, implUtf8, numfixed, fixed)     \
    _WX_VARARG_ITER(_WX_VARARG_MAX_ARGS,                                      \
                    _WX_VARARG_DEFINE_FUNC_VOID,                              \
                    void, name, impl, implUtf8, numfixed, fixed)

// Like WX_DEFINE_VARARG_FUNC_VOID, but instead of wrapping an implementation
// function, does nothing in defined functions' bodies.
//
// Used to implement wxLogXXX functions if wxUSE_LOG=0.
#define WX_DEFINE_VARARG_FUNC_NOP(name, numfixed, fixed)                      \
        _WX_VARARG_DEFINE_FUNC_NOP_N0(name, numfixed, fixed)                  \
        _WX_VARARG_ITER(_WX_VARARG_MAX_ARGS,                                  \
                        _WX_VARARG_DEFINE_FUNC_NOP,                           \
                        void, name, dummy, dummy, numfixed, fixed)

// Like WX_DEFINE_VARARG_FUNC_CTOR, but for defining template constructors
#define WX_DEFINE_VARARG_FUNC_CTOR(name, numfixed, fixed, impl, implUtf8)     \
    _WX_VARARG_DEFINE_FUNC_CTOR_N0(name, impl, implUtf8, numfixed, fixed)     \
    _WX_VARARG_ITER(_WX_VARARG_MAX_ARGS,                                      \
                    _WX_VARARG_DEFINE_FUNC_CTOR,                              \
                    void, name, impl, implUtf8, numfixed, fixed)


// ----------------------------------------------------------------------------
// wxFormatString
// ----------------------------------------------------------------------------

// This class must be used for format string argument of the functions
// defined using WX_DEFINE_VARARG_FUNC_* macros. It converts the string to
// char* or wchar_t* for passing to implementation function efficiently (i.e.
// without keeping the converted string in memory for longer than necessary,
// like c_str()). It also converts format string to the correct form that
// accounts for string changes done by wxArgNormalizer<>
//
// Note that this class can _only_ be used for function arguments!
class WXDLLIMPEXP_BASE wxFormatString
{
public:
#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
    wxFormatString(const char *str)
        : m_char(wxScopedCharBuffer::CreateNonOwned(str)), m_str(nullptr), m_cstr(nullptr) {}
#endif
    wxFormatString(const wchar_t *str)
        : m_wchar(wxScopedWCharBuffer::CreateNonOwned(str)), m_str(nullptr), m_cstr(nullptr) {}
    wxFormatString(const wxString& str)
        : m_str(&str), m_cstr(nullptr) {}
    wxFormatString(const wxCStrData& str)
        : m_str(nullptr), m_cstr(&str) {}
#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
    wxFormatString(const wxScopedCharBuffer& str)
        : m_char(str), m_str(nullptr), m_cstr(nullptr)  {}
#endif
    wxFormatString(const wxScopedWCharBuffer& str)
        : m_wchar(str), m_str(nullptr), m_cstr(nullptr) {}

    // Possible argument types. These are or-combinable for wxASSERT_ARG_TYPE
    // convenience. Some of the values are or-combined with another value, this
    // expresses "supertypes" for use with wxASSERT_ARG_TYPE masks. For example,
    // a char* string is also a pointer and an integer is also a char.
    enum ArgumentType
    {
        Arg_Unused      = 0, // not used at all; the value of 0 is chosen to
                             // conveniently pass wxASSERT_ARG_TYPE's check

        Arg_Char        = 0x0001,    // character as char %c
        Arg_Pointer     = 0x0002,    // %p
        Arg_String      = 0x0004 | Arg_Pointer, // any form of string (%s and %p too)

        Arg_Int         = 0x0008 | Arg_Char, // (ints can be used with %c)
#if SIZEOF_INT == SIZEOF_LONG
        Arg_LongInt     = Arg_Int,
#else
        Arg_LongInt     = 0x0010,
#endif
#if defined(SIZEOF_LONG_LONG) && SIZEOF_LONG_LONG == SIZEOF_LONG
        Arg_LongLongInt = Arg_LongInt,
#else
        Arg_LongLongInt = 0x0020,
#endif

        Arg_Double      = 0x0040,
        Arg_LongDouble  = 0x0080,

#if defined(wxSIZE_T_IS_UINT)
        Arg_Size_t      = Arg_Int,
#elif defined(wxSIZE_T_IS_ULONG)
        Arg_Size_t      = Arg_LongInt,
#elif defined(SIZEOF_LONG_LONG) && SIZEOF_SIZE_T == SIZEOF_LONG_LONG
        Arg_Size_t      = Arg_LongLongInt,
#else
        Arg_Size_t      = 0x0100,
#endif

        Arg_IntPtr      = 0x0200,    // %n -- store # of chars written
        Arg_ShortIntPtr = 0x0400,
        Arg_LongIntPtr  = 0x0800,

        Arg_Unknown     = 0x8000     // unrecognized specifier (likely error)
    };

    // Validate all format string parameters at once: the vector contains the
    // format specifiers corresponding to the actually given arguments.
    void Validate(const std::vector<int>& argTypes) const;

    // returns the type of format specifier for n-th variadic argument (this is
    // not necessarily n-th format specifier if positional specifiers are used);
    // called by wxArgNormalizer<> specializations to get information about
    // n-th variadic argument desired representation
    ArgumentType GetArgumentType(unsigned n) const;

    // returns the value passed to ctor, only converted to wxString, similarly
    // to other InputAsXXX() methods
    wxString InputAsString() const;

#if !wxUSE_UNICODE_WCHAR && !defined wxNO_IMPLICIT_WXSTRING_ENCODING
    operator const char*() const
        { return const_cast<wxFormatString*>(this)->AsChar(); }
private:
    // InputAsChar() returns the value passed to ctor, only converted
    // to char, while AsChar() takes the string returned by InputAsChar()
    // and does format string conversion on it as well (and similarly for
    // ..AsWChar() below)
    const char* InputAsChar();
    const char* AsChar();
    wxScopedCharBuffer m_convertedChar;
#endif // !wxUSE_UNICODE_WCHAR && !defined wx_NO_IMPLICIT_WXSTRING_ENCODING

#if !wxUSE_UTF8_LOCALE_ONLY
public:
    operator const wchar_t*() const
        { return const_cast<wxFormatString*>(this)->AsWChar(); }
private:
    const wchar_t* InputAsWChar();
    const wchar_t* AsWChar();
    wxScopedWCharBuffer m_convertedWChar;
#endif // !wxUSE_UTF8_LOCALE_ONLY

private:
    wxScopedCharBuffer  m_char;
    wxScopedWCharBuffer m_wchar;

    // NB: we can use a pointer here, because wxFormatString is only used
    //     as function argument, so it has shorter life than the string
    //     passed to the ctor
    const wxString * const m_str;
    const wxCStrData * const m_cstr;

    wxDECLARE_NO_ASSIGN_CLASS(wxFormatString);
};

// these two helper classes are used to find wxFormatString argument among fixed
// arguments passed to a vararg template
struct wxFormatStringArgument
{
    wxFormatStringArgument(const wxFormatString *s = nullptr) : m_str(s) {}
    const wxFormatString *m_str;

    // overriding this operator allows us to reuse _WX_VARARG_JOIN macro
    wxFormatStringArgument operator,(const wxFormatStringArgument& a) const
    {
        wxASSERT_MSG( m_str == nullptr || a.m_str == nullptr,
                      "can't have two format strings in vararg function" );
        return wxFormatStringArgument(m_str ? m_str : a.m_str);
    }

    operator const wxFormatString*() const { return m_str; }
};

template<typename T>
struct wxFormatStringArgumentFinder
{
    static wxFormatStringArgument find(T)
    {
        // by default, arguments are not format strings, so return "not found"
        return wxFormatStringArgument();
    }
};

template<>
struct wxFormatStringArgumentFinder<const wxFormatString&>
{
    static wxFormatStringArgument find(const wxFormatString& arg)
        { return wxFormatStringArgument(&arg); }
};

template<>
struct wxFormatStringArgumentFinder<wxFormatString>
    : public wxFormatStringArgumentFinder<const wxFormatString&> {};

// avoid passing big objects by value to wxFormatStringArgumentFinder::find()
// (and especially wx[W]CharBuffer with its auto_ptr<> style semantics!):
template<>
struct wxFormatStringArgumentFinder<wxString>
    : public wxFormatStringArgumentFinder<const wxString&> {};

template<>
struct wxFormatStringArgumentFinder<wxScopedCharBuffer>
    : public wxFormatStringArgumentFinder<const wxScopedCharBuffer&> {
#ifdef wxNO_IMPLICIT_WXSTRING_ENCODING
private:
    wxFormatStringArgumentFinder() wxMEMBER_DELETE;
#endif // wxNO_IMPLICIT_WXSTRING_ENCODING
};

template<>
struct wxFormatStringArgumentFinder<wxScopedWCharBuffer>
    : public wxFormatStringArgumentFinder<const wxScopedWCharBuffer&> {};

template<>
struct wxFormatStringArgumentFinder<wxCharBuffer>
    : public wxFormatStringArgumentFinder<const wxCharBuffer&> {
#ifdef wxNO_IMPLICIT_WXSTRING_ENCODING
private:
    wxFormatStringArgumentFinder() wxMEMBER_DELETE;
#endif // wxNO_IMPLICIT_WXSTRING_ENCODING
};

template<>
struct wxFormatStringArgumentFinder<wxWCharBuffer>
    : public wxFormatStringArgumentFinder<const wxWCharBuffer&> {};


// ----------------------------------------------------------------------------
// wxArgNormalizer*<T> converters
// ----------------------------------------------------------------------------

#if wxDEBUG_LEVEL
    // Check that the format specifier for index-th argument in 'fmt' has
    // the correct type (one of wxFormatString::Arg_XXX or-combination in
    // 'expected_mask').
    #define wxASSERT_ARG_TYPE(fmt, index, expected_mask)                    \
        wxSTATEMENT_MACRO_BEGIN                                             \
            if ( !fmt )                                                     \
                break;                                                      \
            const int argtype = fmt->GetArgumentType(index);                \
            wxASSERT_MSG( (argtype & (expected_mask)) == argtype,           \
                          "format specifier doesn't match argument type" ); \
        wxSTATEMENT_MACRO_END
#else
    // Just define it to suppress "unused parameter" warnings for the
    // parameters which we don't use otherwise
    #define wxASSERT_ARG_TYPE(fmt, index, expected_mask)                      \
        wxUnusedVar(fmt);                                                     \
        wxUnusedVar(index)

    // Also provide a trivial implementation of Validate() doing nothing in
    // this case.
    inline void
    wxFormatString::Validate(const std::vector<int>& WXUNUSED(argTypes)) const
    {
    }
#endif // wxDEBUG_LEVEL/!wxDEBUG_LEVEL


// Note: this type is misnamed, so that the error message is easier to
// understand (no error happens for enums, because the IsEnum=true case is
// specialized).
template<bool IsEnum>
struct wxFormatStringSpecifierNonPodType {};

template<>
struct wxFormatStringSpecifierNonPodType<true>
{
    enum { value = wxFormatString::Arg_Int };
};

template<typename T>
struct wxFormatStringSpecifier
{
    typedef std::is_enum<T> is_enum;
    enum { value = wxFormatStringSpecifierNonPodType<is_enum::value>::value };
};

template<typename T>
struct wxFormatStringSpecifier<T*>
{
    enum { value = wxFormatString::Arg_Pointer };
};

template<typename T>
struct wxFormatStringSpecifier<const T*>
{
    enum { value = wxFormatString::Arg_Pointer };
};


#define wxFORMAT_STRING_SPECIFIER(T, arg)                                   \
    template<> struct wxFormatStringSpecifier<T>                            \
    {                                                                       \
        enum { value = arg };                                               \
    };

#define wxDISABLED_FORMAT_STRING_SPECIFIER(T)                               \
    template<> struct wxFormatStringSpecifier<T>                            \
    {                                                                       \
    private:                                                                \
        wxFormatStringSpecifier() wxMEMBER_DELETE;                          \
    };

wxFORMAT_STRING_SPECIFIER(bool, wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(char, wxFormatString::Arg_Char | wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(signed char, wxFormatString::Arg_Char | wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(unsigned char, wxFormatString::Arg_Char | wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(int, wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(unsigned int, wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(short int, wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(short unsigned int, wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(long int, wxFormatString::Arg_LongInt)
wxFORMAT_STRING_SPECIFIER(long unsigned int, wxFormatString::Arg_LongInt)
wxFORMAT_STRING_SPECIFIER(wxLongLong_t, wxFormatString::Arg_LongLongInt)
wxFORMAT_STRING_SPECIFIER(wxULongLong_t, wxFormatString::Arg_LongLongInt)
wxFORMAT_STRING_SPECIFIER(float, wxFormatString::Arg_Double)
wxFORMAT_STRING_SPECIFIER(double, wxFormatString::Arg_Double)
wxFORMAT_STRING_SPECIFIER(long double, wxFormatString::Arg_LongDouble)

#if wxWCHAR_T_IS_REAL_TYPE
wxFORMAT_STRING_SPECIFIER(wchar_t, wxFormatString::Arg_Char | wxFormatString::Arg_Int)
#endif
wxFORMAT_STRING_SPECIFIER(wxUniChar, wxFormatString::Arg_Char | wxFormatString::Arg_Int)
wxFORMAT_STRING_SPECIFIER(wxUniCharRef, wxFormatString::Arg_Char | wxFormatString::Arg_Int)

#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
wxFORMAT_STRING_SPECIFIER(char*, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(unsigned char*, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(signed char*, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(const char*, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(const unsigned char*, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(const signed char*, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(wxCharBuffer, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(wxScopedCharBuffer, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(std::string, wxFormatString::Arg_String)
#ifdef __cpp_lib_string_view
wxFORMAT_STRING_SPECIFIER(std::string_view, wxFormatString::Arg_String)
#endif
#else // wxNO_IMPLICIT_WXSTRING_ENCODING
wxDISABLED_FORMAT_STRING_SPECIFIER(char*)
wxDISABLED_FORMAT_STRING_SPECIFIER(unsigned char*)
wxDISABLED_FORMAT_STRING_SPECIFIER(signed char*)
wxDISABLED_FORMAT_STRING_SPECIFIER(const char*)
wxDISABLED_FORMAT_STRING_SPECIFIER(const unsigned char*)
wxDISABLED_FORMAT_STRING_SPECIFIER(const signed char*)
#endif // wxNO_IMPLICIT_WXSTRING_ENCODING
wxFORMAT_STRING_SPECIFIER(wchar_t*, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(const wchar_t*, wxFormatString::Arg_String)

wxFORMAT_STRING_SPECIFIER(wxWCharBuffer, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(wxScopedWCharBuffer, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(wxString, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(wxCStrData, wxFormatString::Arg_String)
wxFORMAT_STRING_SPECIFIER(std::wstring, wxFormatString::Arg_String)

wxFORMAT_STRING_SPECIFIER(int*, wxFormatString::Arg_IntPtr | wxFormatString::Arg_Pointer)
wxFORMAT_STRING_SPECIFIER(short int*, wxFormatString::Arg_ShortIntPtr | wxFormatString::Arg_Pointer)
wxFORMAT_STRING_SPECIFIER(long int*, wxFormatString::Arg_LongIntPtr | wxFormatString::Arg_Pointer)

#ifdef wxHAS_NULLPTR_T
wxFORMAT_STRING_SPECIFIER(std::nullptr_t, wxFormatString::Arg_Pointer)
#endif

#undef wxFORMAT_STRING_SPECIFIER
#undef wxDISABLED_FORMAT_STRING_SPECIFIER


// Converts an argument passed to wxPrint etc. into standard form expected,
// by wxXXX functions, e.g. all strings (wxString, char*, wchar_t*) are
// converted into wchar_t* or char* depending on the build.
template<typename T>
struct wxArgNormalizer
{
    // Ctor. 'value' is the value passed as variadic argument, 'fmt' is pointer
    // to printf-like format string or nullptr if the variadic function doesn't
    // use format string and 'index' is index of 'value' in variadic arguments
    // list (starting at 1)
    //
    // Because the format string and index are used for checking for the format
    // specifier mismatches and can be nullptr and 0, respectively, if they had
    // been already checked using wxFormatString::Validate().
    wxArgNormalizer(T value,
                    const wxFormatString *fmt, unsigned index)
        : m_value(value)
    {
        wxASSERT_ARG_TYPE( fmt, index, wxFormatStringSpecifier<T>::value );
    }

    // Returns the value in a form that can be safely passed to real vararg
    // functions. In case of strings, this is char* in UTF-8-only build and
    // wchar_t* otherwise.
    T get() const { return m_value; }

    T m_value;
};

// normalizer for passing arguments to functions working with wchar_t*
// string representation
#if !wxUSE_UTF8_LOCALE_ONLY
template<typename T>
struct wxArgNormalizerWchar : public wxArgNormalizer<T>
{
    wxArgNormalizerWchar(T value,
                         const wxFormatString *fmt, unsigned index)
        : wxArgNormalizer<T>(value, fmt, index) {}
};

#endif // !wxUSE_UTF8_LOCALE_ONLY

// normalizer for passing arguments to functions working with UTF-8 encoded
// char* strings
#if wxUSE_UNICODE_UTF8
    template<typename T>
    struct wxArgNormalizerUtf8 : public wxArgNormalizer<T>
    {
        wxArgNormalizerUtf8(T value,
                            const wxFormatString *fmt, unsigned index)
            : wxArgNormalizer<T>(value, fmt, index) {}
    };

    #define wxArgNormalizerNative wxArgNormalizerUtf8
#else // wxUSE_UNICODE_WCHAR
    #define wxArgNormalizerNative wxArgNormalizerWchar
#endif // wxUSE_UNICODE_UTF8/wxUSE_UNICODE_WCHAR



// special cases for converting strings:


// base class for wxArgNormalizer<T> specializations that need to do conversion;
// CharType is either wxStringCharType or wchar_t in UTF-8 build when wrapping
// widechar CRT function
template<typename CharType>
struct wxArgNormalizerWithBuffer
{
    typedef wxScopedCharTypeBuffer<CharType> CharBuffer;

    wxArgNormalizerWithBuffer() = default;
    wxArgNormalizerWithBuffer(const CharBuffer& buf,
                              const wxFormatString *fmt,
                              unsigned index)
        : m_value(buf)
    {
        wxASSERT_ARG_TYPE( fmt, index, wxFormatString::Arg_String );
    }

    const CharType *get() const { return m_value; }

    CharBuffer m_value;
};

// string objects:
template<>
struct WXDLLIMPEXP_BASE wxArgNormalizerNative<const wxString&>
{
    wxArgNormalizerNative(const wxString& s,
                          const wxFormatString *fmt,
                          unsigned index)
        : m_value(s)
    {
        wxASSERT_ARG_TYPE( fmt, index, wxFormatString::Arg_String );
    }

    const wxStringCharType *get() const;

    const wxString& m_value;
};

// c_str() values:
template<>
struct WXDLLIMPEXP_BASE wxArgNormalizerNative<const wxCStrData&>
{
    wxArgNormalizerNative(const wxCStrData& value,
                          const wxFormatString *fmt,
                          unsigned index)
        : m_value(value)
    {
        wxASSERT_ARG_TYPE( fmt, index, wxFormatString::Arg_String );
    }

    const wxStringCharType *get() const;

    const wxCStrData& m_value;
};

// wxString/wxCStrData conversion to wchar_t* value
#if wxUSE_UNICODE_UTF8 && !wxUSE_UTF8_LOCALE_ONLY
template<>
struct WXDLLIMPEXP_BASE wxArgNormalizerWchar<const wxString&>
    : public wxArgNormalizerWithBuffer<wchar_t>
{
    wxArgNormalizerWchar(const wxString& s,
                         const wxFormatString *fmt, unsigned index);
};

template<>
struct WXDLLIMPEXP_BASE wxArgNormalizerWchar<const wxCStrData&>
    : public wxArgNormalizerWithBuffer<wchar_t>
{
    wxArgNormalizerWchar(const wxCStrData& s,
                         const wxFormatString *fmt, unsigned index);
};
#endif // wxUSE_UNICODE_UTF8 && !wxUSE_UTF8_LOCALE_ONLY


// C string pointers of the wrong type (wchar_t* for UTF-8-only build,
// char* otherwise):
#if wxUSE_UNICODE_WCHAR

#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
template<>
struct wxArgNormalizerWchar<const char*>
    : public wxArgNormalizerWithBuffer<wchar_t>
{
    wxArgNormalizerWchar(const char* s,
                         const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerWithBuffer<wchar_t>(wxConvLibc.cMB2WC(s), fmt, index) {}
};
#endif // wxNO_IMPLICIT_WXSTRING_ENCODING

#else // wxUSE_UNICODE_UTF8

template<>
struct wxArgNormalizerUtf8<const wchar_t*>
    : public wxArgNormalizerWithBuffer<char>
{
    wxArgNormalizerUtf8(const wchar_t* s,
                        const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerWithBuffer<char>(wxConvUTF8.cWC2MB(s), fmt, index) {}
};

#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
template<>
struct wxArgNormalizerUtf8<const char*>
    : public wxArgNormalizerWithBuffer<char>
{
    wxArgNormalizerUtf8(const char* s,
                        const wxFormatString *fmt,
                        unsigned index)
    {
        wxASSERT_ARG_TYPE( fmt, index, wxFormatString::Arg_String );

        if ( wxLocaleIsUtf8 )
        {
            m_value = wxScopedCharBuffer::CreateNonOwned(s);
        }
        else
        {
            // convert to widechar string first:
            wxScopedWCharBuffer buf(wxConvLibc.cMB2WC(s));

            // then to UTF-8:
            if ( buf )
                m_value = wxConvUTF8.cWC2MB(buf);
        }
    }
};
#endif

// UTF-8 build needs conversion to wchar_t* too:
#if !wxUSE_UTF8_LOCALE_ONLY && !defined wxNO_IMPLICIT_WXSTRING_ENCODING
template<>
struct wxArgNormalizerWchar<const char*>
    : public wxArgNormalizerWithBuffer<wchar_t>
{
    wxArgNormalizerWchar(const char* s,
                         const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerWithBuffer<wchar_t>(wxConvLibc.cMB2WC(s), fmt, index) {}
};
#endif // !wxUSE_UTF8_LOCALE_ONLY && !defined wxNO_IMPLICIT_WXSTRING_ENCODING

#endif // wxUSE_UNICODE_WCHAR/wxUSE_UNICODE_UTF8


#ifdef wxNO_IMPLICIT_WXSTRING_ENCODING
// wxArgNormalizer specializations that cannot be instanced
template<>
struct wxArgNormalizer<const char*> {
private:
    wxArgNormalizer(const char*, const wxFormatString *, unsigned);
    const char *get() const;
};
template<>
struct wxArgNormalizer<char*> {
private:
    wxArgNormalizer(const char*, const wxFormatString *, unsigned);
    char *get() const;
};
template<>
struct wxArgNormalizer<const std::string> {
private:
    wxArgNormalizer(const std::string&, const wxFormatString *, unsigned);
    std::string get() const;
};
template<>
struct wxArgNormalizer<std::string> {
private:
    wxArgNormalizer(std::string&, const wxFormatString *, unsigned);
    std::string get() const;
};
template<>
struct wxArgNormalizer<wxCharBuffer> {
private:
    wxArgNormalizer(wxCharBuffer&, const wxFormatString *, unsigned);
    std::string get() const;
};
template<>
struct wxArgNormalizer<wxScopedCharBuffer> {
private:
    wxArgNormalizer(wxScopedCharBuffer&, const wxFormatString *, unsigned);
    std::string get() const;
};
#endif // wxNO_IMPLICIT_WXSTRING_ENCODING

// this macro is used to implement specialization that are exactly same as
// some other specialization, i.e. to "forward" the implementation (e.g. for
// T=wxString and T=const wxString&). Note that the ctor takes BaseT argument,
// not T!
#if wxUSE_UNICODE_UTF8
    #if wxUSE_UTF8_LOCALE_ONLY
        #define WX_ARG_NORMALIZER_FORWARD(T, BaseT)                         \
          _WX_ARG_NORMALIZER_FORWARD_IMPL(wxArgNormalizerUtf8, T, BaseT)
    #else // possibly non-UTF8 locales
        #define WX_ARG_NORMALIZER_FORWARD(T, BaseT)                         \
          _WX_ARG_NORMALIZER_FORWARD_IMPL(wxArgNormalizerWchar, T, BaseT);  \
          _WX_ARG_NORMALIZER_FORWARD_IMPL(wxArgNormalizerUtf8, T, BaseT)
    #endif
#else // wxUSE_UNICODE_WCHAR
    #define WX_ARG_NORMALIZER_FORWARD(T, BaseT)                             \
        _WX_ARG_NORMALIZER_FORWARD_IMPL(wxArgNormalizerWchar, T, BaseT)
#endif // wxUSE_UNICODE_UTF8/wxUSE_UNICODE_WCHAR

#define _WX_ARG_NORMALIZER_FORWARD_IMPL(Normalizer, T, BaseT)               \
    template<>                                                              \
    struct Normalizer<T> : public Normalizer<BaseT>                         \
    {                                                                       \
        Normalizer(BaseT value,                                             \
                   const wxFormatString *fmt, unsigned index)               \
            : Normalizer<BaseT>(value, fmt, index) {}                       \
    }

// non-reference versions of specializations for string objects
WX_ARG_NORMALIZER_FORWARD(wxString, const wxString&);
WX_ARG_NORMALIZER_FORWARD(wxCStrData, const wxCStrData&);

// versions for passing non-const pointers:
#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
WX_ARG_NORMALIZER_FORWARD(char*, const char*);
#endif
WX_ARG_NORMALIZER_FORWARD(wchar_t*, const wchar_t*);

// versions for passing wx[W]CharBuffer:
#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
WX_ARG_NORMALIZER_FORWARD(wxScopedCharBuffer, const char*);
WX_ARG_NORMALIZER_FORWARD(const wxScopedCharBuffer&, const char*);
#endif
WX_ARG_NORMALIZER_FORWARD(wxScopedWCharBuffer, const wchar_t*);
WX_ARG_NORMALIZER_FORWARD(const wxScopedWCharBuffer&, const wchar_t*);
#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
WX_ARG_NORMALIZER_FORWARD(wxCharBuffer, const char*);
WX_ARG_NORMALIZER_FORWARD(const wxCharBuffer&, const char*);
#endif
WX_ARG_NORMALIZER_FORWARD(wxWCharBuffer, const wchar_t*);
WX_ARG_NORMALIZER_FORWARD(const wxWCharBuffer&, const wchar_t*);

// versions for std::[w]string and string_view, if we have it.
#if !wxUSE_UTF8_LOCALE_ONLY
#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
template<>
struct wxArgNormalizerWchar<const std::string&>
    : public wxArgNormalizerWchar<const char*>
{
    wxArgNormalizerWchar(const std::string& s,
                         const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerWchar<const char*>(s.c_str(), fmt, index) {}
};

#ifdef __cpp_lib_string_view
// This is inefficient because we create a temporary string rather than using
// the string_view directly, but is required because the rest of the code
// assumes NUL-terminated strings and is still better than nothing (i.e. no
// support for std::string_view at all).
template<>
struct wxArgNormalizerWchar<const std::string_view&>
    : public wxArgNormalizerWchar<const std::string&>
{
    wxArgNormalizerWchar(const std::string_view& v,
                         const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerWchar<const std::string&>(std::string{v}, fmt, index) {}
};
#endif // __cpp_lib_string_view

#endif // NO_IMPLICIT_WXSTRING_ENCODING

template<>
struct wxArgNormalizerWchar<const std::wstring&>
    : public wxArgNormalizerWchar<const wchar_t*>
{
    wxArgNormalizerWchar(const std::wstring& s,
                         const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerWchar<const wchar_t*>(s.c_str(), fmt, index) {}
};
#endif // !wxUSE_UTF8_LOCALE_ONLY

#if wxUSE_UNICODE_UTF8
#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
template<>
struct wxArgNormalizerUtf8<const std::string&>
    : public wxArgNormalizerUtf8<const char*>
{
    wxArgNormalizerUtf8(const std::string& s,
                        const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerUtf8<const char*>(s.c_str(), fmt, index) {}
};

#ifdef __cpp_lib_string_view
template<>
struct wxArgNormalizerUtf8<const std::string_view&>
{
    wxArgNormalizerUtf8(const std::string_view& v,
                        const wxFormatString *fmt, unsigned index)
        : m_str{v}
    {
        wxASSERT_ARG_TYPE( fmt, index, wxFormatString::Arg_String );
    }

    const char* get() const { return m_str.c_str(); }

    // We need to store this string to ensure that we use a NUL-terminated
    // buffer, i.e. we can't use string_view data directly.
    const std::string m_str;
};
#endif // __cpp_lib_string_view

#endif // wxNO_IMPLICIT_WXSTRING_ENCODING

template<>
struct wxArgNormalizerUtf8<const std::wstring&>
    : public wxArgNormalizerUtf8<const wchar_t*>
{
    wxArgNormalizerUtf8(const std::wstring& s,
                        const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerUtf8<const wchar_t*>(s.c_str(), fmt, index) {}
};
#endif // wxUSE_UNICODE_UTF8

#ifndef wxNO_IMPLICIT_WXSTRING_ENCODING
WX_ARG_NORMALIZER_FORWARD(std::string, const std::string&);
#ifdef __cpp_lib_string_view
WX_ARG_NORMALIZER_FORWARD(std::string_view, const std::string_view&);
#endif // __cpp_lib_string_view
#endif
WX_ARG_NORMALIZER_FORWARD(std::wstring, const std::wstring&);


// versions for wxUniChar, wxUniCharRef:
// (this is same for UTF-8 and Wchar builds, we just convert to wchar_t)
template<>
struct wxArgNormalizer<const wxUniChar&> : public wxArgNormalizer<wchar_t>
{
    wxArgNormalizer(const wxUniChar& s,
                    const wxFormatString *fmt, unsigned index)
        : wxArgNormalizer<wchar_t>(wx_truncate_cast(wchar_t, s.GetValue()), fmt, index) {}
};

// for wchar_t, default handler does the right thing

// char has to be treated differently: a char argument may
// be used either for a character value (which should be converted into
// wxUniChar) or as an integer value (which should be left as-is). We take
// advantage of the fact that both char and wchar_t are converted into int
// in variadic arguments here.
template<typename T>
struct wxArgNormalizerNarrowChar
{
    wxArgNormalizerNarrowChar(T value,
                              const wxFormatString *fmt, unsigned index)
    {
        wxASSERT_ARG_TYPE( fmt, index,
                           wxFormatString::Arg_Char | wxFormatString::Arg_Int );

        if ( fmt && fmt->GetArgumentType(index) == wxFormatString::Arg_Char )
            m_value = wx_truncate_cast(T, wxUniChar(value).GetValue());
        else
            m_value = value;
    }

    int get() const { return m_value; }

    T m_value;
};

template<>
struct wxArgNormalizer<char> : public wxArgNormalizerNarrowChar<char>
{
    wxArgNormalizer(char value,
                    const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerNarrowChar<char>(value, fmt, index) {}
};

template<>
struct wxArgNormalizer<unsigned char>
    : public wxArgNormalizerNarrowChar<unsigned char>
{
    wxArgNormalizer(unsigned char value,
                    const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerNarrowChar<unsigned char>(value, fmt, index) {}
};

template<>
struct wxArgNormalizer<signed char>
    : public wxArgNormalizerNarrowChar<signed char>
{
    wxArgNormalizer(signed char value,
                    const wxFormatString *fmt, unsigned index)
        : wxArgNormalizerNarrowChar<signed char>(value, fmt, index) {}
};

// convert references:
WX_ARG_NORMALIZER_FORWARD(wxUniChar, const wxUniChar&);
WX_ARG_NORMALIZER_FORWARD(const wxUniCharRef&, const wxUniChar&);
WX_ARG_NORMALIZER_FORWARD(wxUniCharRef, const wxUniChar&);
WX_ARG_NORMALIZER_FORWARD(const wchar_t&, wchar_t);

WX_ARG_NORMALIZER_FORWARD(const char&, char);
WX_ARG_NORMALIZER_FORWARD(const unsigned char&, unsigned char);
WX_ARG_NORMALIZER_FORWARD(const signed char&, signed char);


#undef WX_ARG_NORMALIZER_FORWARD
#undef _WX_ARG_NORMALIZER_FORWARD_IMPL

// NB: Don't #undef wxASSERT_ARG_TYPE here as it's also used in wx/longlong.h.

// ----------------------------------------------------------------------------
// WX_VA_ARG_STRING
// ----------------------------------------------------------------------------

// Replacement for va_arg() for use with strings in functions that accept
// strings normalized by wxArgNormalizer<T>:

struct WXDLLIMPEXP_BASE wxArgNormalizedString
{
    wxArgNormalizedString(const void* ptr) : m_ptr(ptr) {}

    // returns true if non-null string was passed in
    bool IsValid() const { return m_ptr != nullptr; }
    operator bool() const { return IsValid(); }

    // extracts the string, returns empty string if nullptr was passed in
    wxString GetString() const;
    operator wxString() const;

private:
    const void *m_ptr;
};

#define WX_VA_ARG_STRING(ap) wxArgNormalizedString(va_arg(ap, const void*))

// ----------------------------------------------------------------------------
// implementation of the WX_DEFINE_VARARG_* macros
// ----------------------------------------------------------------------------

// NB: The vararg emulation code is limited to 30 variadic and 4 fixed
//     arguments at the moment.
//     If you need more variadic arguments, you need to
//        1) increase the value of _WX_VARARG_MAX_ARGS
//        2) add _WX_VARARG_JOIN_* and _WX_VARARG_ITER_* up to the new
//           _WX_VARARG_MAX_ARGS value to the lists below
//     If you need more fixed arguments, you need to
//        1) increase the value of _WX_VARARG_MAX_FIXED_ARGS
//        2) add _WX_VARARG_FIXED_EXPAND_* and _WX_VARARG_FIXED_UNUSED_EXPAND_*
//           macros below
#define _WX_VARARG_MAX_ARGS        30
#define _WX_VARARG_MAX_FIXED_ARGS   4

#define _WX_VARARG_JOIN_1(m)                                 m(1)
#define _WX_VARARG_JOIN_2(m)       _WX_VARARG_JOIN_1(m),     m(2)
#define _WX_VARARG_JOIN_3(m)       _WX_VARARG_JOIN_2(m),     m(3)
#define _WX_VARARG_JOIN_4(m)       _WX_VARARG_JOIN_3(m),     m(4)
#define _WX_VARARG_JOIN_5(m)       _WX_VARARG_JOIN_4(m),     m(5)
#define _WX_VARARG_JOIN_6(m)       _WX_VARARG_JOIN_5(m),     m(6)
#define _WX_VARARG_JOIN_7(m)       _WX_VARARG_JOIN_6(m),     m(7)
#define _WX_VARARG_JOIN_8(m)       _WX_VARARG_JOIN_7(m),     m(8)
#define _WX_VARARG_JOIN_9(m)       _WX_VARARG_JOIN_8(m),     m(9)
#define _WX_VARARG_JOIN_10(m)      _WX_VARARG_JOIN_9(m),     m(10)
#define _WX_VARARG_JOIN_11(m)      _WX_VARARG_JOIN_10(m),    m(11)
#define _WX_VARARG_JOIN_12(m)      _WX_VARARG_JOIN_11(m),    m(12)
#define _WX_VARARG_JOIN_13(m)      _WX_VARARG_JOIN_12(m),    m(13)
#define _WX_VARARG_JOIN_14(m)      _WX_VARARG_JOIN_13(m),    m(14)
#define _WX_VARARG_JOIN_15(m)      _WX_VARARG_JOIN_14(m),    m(15)
#define _WX_VARARG_JOIN_16(m)      _WX_VARARG_JOIN_15(m),    m(16)
#define _WX_VARARG_JOIN_17(m)      _WX_VARARG_JOIN_16(m),    m(17)
#define _WX_VARARG_JOIN_18(m)      _WX_VARARG_JOIN_17(m),    m(18)
#define _WX_VARARG_JOIN_19(m)      _WX_VARARG_JOIN_18(m),    m(19)
#define _WX_VARARG_JOIN_20(m)      _WX_VARARG_JOIN_19(m),    m(20)
#define _WX_VARARG_JOIN_21(m)      _WX_VARARG_JOIN_20(m),    m(21)
#define _WX_VARARG_JOIN_22(m)      _WX_VARARG_JOIN_21(m),    m(22)
#define _WX_VARARG_JOIN_23(m)      _WX_VARARG_JOIN_22(m),    m(23)
#define _WX_VARARG_JOIN_24(m)      _WX_VARARG_JOIN_23(m),    m(24)
#define _WX_VARARG_JOIN_25(m)      _WX_VARARG_JOIN_24(m),    m(25)
#define _WX_VARARG_JOIN_26(m)      _WX_VARARG_JOIN_25(m),    m(26)
#define _WX_VARARG_JOIN_27(m)      _WX_VARARG_JOIN_26(m),    m(27)
#define _WX_VARARG_JOIN_28(m)      _WX_VARARG_JOIN_27(m),    m(28)
#define _WX_VARARG_JOIN_29(m)      _WX_VARARG_JOIN_28(m),    m(29)
#define _WX_VARARG_JOIN_30(m)      _WX_VARARG_JOIN_29(m),    m(30)

#define _WX_VARARG_ITER_1(m,a,b,c,d,e,f)                                    m(1,a,b,c,d,e,f)
#define _WX_VARARG_ITER_2(m,a,b,c,d,e,f)  _WX_VARARG_ITER_1(m,a,b,c,d,e,f)  m(2,a,b,c,d,e,f)
#define _WX_VARARG_ITER_3(m,a,b,c,d,e,f)  _WX_VARARG_ITER_2(m,a,b,c,d,e,f)  m(3,a,b,c,d,e,f)
#define _WX_VARARG_ITER_4(m,a,b,c,d,e,f)  _WX_VARARG_ITER_3(m,a,b,c,d,e,f)  m(4,a,b,c,d,e,f)
#define _WX_VARARG_ITER_5(m,a,b,c,d,e,f)  _WX_VARARG_ITER_4(m,a,b,c,d,e,f)  m(5,a,b,c,d,e,f)
#define _WX_VARARG_ITER_6(m,a,b,c,d,e,f)  _WX_VARARG_ITER_5(m,a,b,c,d,e,f)  m(6,a,b,c,d,e,f)
#define _WX_VARARG_ITER_7(m,a,b,c,d,e,f)  _WX_VARARG_ITER_6(m,a,b,c,d,e,f)  m(7,a,b,c,d,e,f)
#define _WX_VARARG_ITER_8(m,a,b,c,d,e,f)  _WX_VARARG_ITER_7(m,a,b,c,d,e,f)  m(8,a,b,c,d,e,f)
#define _WX_VARARG_ITER_9(m,a,b,c,d,e,f)  _WX_VARARG_ITER_8(m,a,b,c,d,e,f)  m(9,a,b,c,d,e,f)
#define _WX_VARARG_ITER_10(m,a,b,c,d,e,f) _WX_VARARG_ITER_9(m,a,b,c,d,e,f)  m(10,a,b,c,d,e,f)
#define _WX_VARARG_ITER_11(m,a,b,c,d,e,f) _WX_VARARG_ITER_10(m,a,b,c,d,e,f) m(11,a,b,c,d,e,f)
#define _WX_VARARG_ITER_12(m,a,b,c,d,e,f) _WX_VARARG_ITER_11(m,a,b,c,d,e,f) m(12,a,b,c,d,e,f)
#define _WX_VARARG_ITER_13(m,a,b,c,d,e,f) _WX_VARARG_ITER_12(m,a,b,c,d,e,f) m(13,a,b,c,d,e,f)
#define _WX_VARARG_ITER_14(m,a,b,c,d,e,f) _WX_VARARG_ITER_13(m,a,b,c,d,e,f) m(14,a,b,c,d,e,f)
#define _WX_VARARG_ITER_15(m,a,b,c,d,e,f) _WX_VARARG_ITER_14(m,a,b,c,d,e,f) m(15,a,b,c,d,e,f)
#define _WX_VARARG_ITER_16(m,a,b,c,d,e,f) _WX_VARARG_ITER_15(m,a,b,c,d,e,f) m(16,a,b,c,d,e,f)
#define _WX_VARARG_ITER_17(m,a,b,c,d,e,f) _WX_VARARG_ITER_16(m,a,b,c,d,e,f) m(17,a,b,c,d,e,f)
#define _WX_VARARG_ITER_18(m,a,b,c,d,e,f) _WX_VARARG_ITER_17(m,a,b,c,d,e,f) m(18,a,b,c,d,e,f)
#define _WX_VARARG_ITER_19(m,a,b,c,d,e,f) _WX_VARARG_ITER_18(m,a,b,c,d,e,f) m(19,a,b,c,d,e,f)
#define _WX_VARARG_ITER_20(m,a,b,c,d,e,f) _WX_VARARG_ITER_19(m,a,b,c,d,e,f) m(20,a,b,c,d,e,f)
#define _WX_VARARG_ITER_21(m,a,b,c,d,e,f) _WX_VARARG_ITER_20(m,a,b,c,d,e,f) m(21,a,b,c,d,e,f)
#define _WX_VARARG_ITER_22(m,a,b,c,d,e,f) _WX_VARARG_ITER_21(m,a,b,c,d,e,f) m(22,a,b,c,d,e,f)
#define _WX_VARARG_ITER_23(m,a,b,c,d,e,f) _WX_VARARG_ITER_22(m,a,b,c,d,e,f) m(23,a,b,c,d,e,f)
#define _WX_VARARG_ITER_24(m,a,b,c,d,e,f) _WX_VARARG_ITER_23(m,a,b,c,d,e,f) m(24,a,b,c,d,e,f)
#define _WX_VARARG_ITER_25(m,a,b,c,d,e,f) _WX_VARARG_ITER_24(m,a,b,c,d,e,f) m(25,a,b,c,d,e,f)
#define _WX_VARARG_ITER_26(m,a,b,c,d,e,f) _WX_VARARG_ITER_25(m,a,b,c,d,e,f) m(26,a,b,c,d,e,f)
#define _WX_VARARG_ITER_27(m,a,b,c,d,e,f) _WX_VARARG_ITER_26(m,a,b,c,d,e,f) m(27,a,b,c,d,e,f)
#define _WX_VARARG_ITER_28(m,a,b,c,d,e,f) _WX_VARARG_ITER_27(m,a,b,c,d,e,f) m(28,a,b,c,d,e,f)
#define _WX_VARARG_ITER_29(m,a,b,c,d,e,f) _WX_VARARG_ITER_28(m,a,b,c,d,e,f) m(29,a,b,c,d,e,f)
#define _WX_VARARG_ITER_30(m,a,b,c,d,e,f) _WX_VARARG_ITER_29(m,a,b,c,d,e,f) m(30,a,b,c,d,e,f)


#define _WX_VARARG_FIXED_EXPAND_1(t1) \
         t1 f1
#define _WX_VARARG_FIXED_EXPAND_2(t1,t2) \
         t1 f1, t2 f2
#define _WX_VARARG_FIXED_EXPAND_3(t1,t2,t3) \
         t1 f1, t2 f2, t3 f3
#define _WX_VARARG_FIXED_EXPAND_4(t1,t2,t3,t4) \
         t1 f1, t2 f2, t3 f3, t4 f4

#define _WX_VARARG_FIXED_UNUSED_EXPAND_1(t1) \
         t1 WXUNUSED(f1)
#define _WX_VARARG_FIXED_UNUSED_EXPAND_2(t1,t2) \
         t1 WXUNUSED(f1), t2 WXUNUSED(f2)
#define _WX_VARARG_FIXED_UNUSED_EXPAND_3(t1,t2,t3) \
         t1 WXUNUSED(f1), t2 WXUNUSED(f2), t3 WXUNUSED(f3)
#define _WX_VARARG_FIXED_UNUSED_EXPAND_4(t1,t2,t3,t4) \
         t1 WXUNUSED(f1), t2 WXUNUSED(f2), t3 WXUNUSED(f3), t4 WXUNUSED(f4)

#define _WX_VARARG_FIXED_TYPEDEFS_1(t1) \
             typedef t1 TF1
#define _WX_VARARG_FIXED_TYPEDEFS_2(t1,t2) \
             _WX_VARARG_FIXED_TYPEDEFS_1(t1); typedef t2 TF2
#define _WX_VARARG_FIXED_TYPEDEFS_3(t1,t2,t3) \
             _WX_VARARG_FIXED_TYPEDEFS_2(t1,t2); typedef t3 TF3
#define _WX_VARARG_FIXED_TYPEDEFS_4(t1,t2,t3,t4) \
             _WX_VARARG_FIXED_TYPEDEFS_3(t1,t2,t3); typedef t4 TF4

// This macro expands N-items tuple of fixed arguments types into part of
// function's declaration. For example,
// "_WX_VARARG_FIXED_EXPAND(3, (int, char*, int))" expands into
// "int f1, char* f2, int f3".
#define _WX_VARARG_FIXED_EXPAND(N, args) \
                _WX_VARARG_FIXED_EXPAND_IMPL(N, args)
#define _WX_VARARG_FIXED_EXPAND_IMPL(N, args) \
                _WX_VARARG_FIXED_EXPAND_##N args

// Ditto for unused arguments
#define _WX_VARARG_FIXED_UNUSED_EXPAND(N, args) \
                _WX_VARARG_FIXED_UNUSED_EXPAND_IMPL(N, args)
#define _WX_VARARG_FIXED_UNUSED_EXPAND_IMPL(N, args) \
                _WX_VARARG_FIXED_UNUSED_EXPAND_##N args

// Declarates typedefs for fixed arguments types; i-th fixed argument types
// will have TFi typedef.
#define _WX_VARARG_FIXED_TYPEDEFS(N, args) \
                _WX_VARARG_FIXED_TYPEDEFS_IMPL(N, args)
#define _WX_VARARG_FIXED_TYPEDEFS_IMPL(N, args) \
                _WX_VARARG_FIXED_TYPEDEFS_##N args


// This macro calls another macro 'm' passed as second argument 'N' times,
// with its only argument set to 1..N, and concatenates the results using
// comma as separator.
//
// An example:
//     #define foo(i)  x##i
//     // this expands to "x1,x2,x3,x4"
//     _WX_VARARG_JOIN(4, foo)
//
//
// N must not be greater than _WX_VARARG_MAX_ARGS (=30).
#define _WX_VARARG_JOIN(N, m)             _WX_VARARG_JOIN_IMPL(N, m)
#define _WX_VARARG_JOIN_IMPL(N, m)        _WX_VARARG_JOIN_##N(m)


// This macro calls another macro 'm' passed as second argument 'N' times, with
// its first argument set to 1..N and the remaining arguments set to 'a', 'b',
// 'c', 'd', 'e' and 'f'. The results are separated with whitespace in the
// expansion.
//
// An example:
//     // this macro expands to:
//     //     foo(1,a,b,c,d,e,f)
//     //     foo(2,a,b,c,d,e,f)
//     //     foo(3,a,b,c,d,e,f)
//     _WX_VARARG_ITER(3, foo, a, b, c, d, e, f)
//
// N must not be greater than _WX_VARARG_MAX_ARGS (=30).
#define _WX_VARARG_ITER(N,m,a,b,c,d,e,f) \
        _WX_VARARG_ITER_IMPL(N,m,a,b,c,d,e,f)
#define _WX_VARARG_ITER_IMPL(N,m,a,b,c,d,e,f) \
        _WX_VARARG_ITER_##N(m,a,b,c,d,e,f)

// Generates code snippet for i-th "variadic" argument in vararg function's
// prototype:
#define _WX_VARARG_ARG(i)               T##i a##i

// Like _WX_VARARG_ARG_UNUSED, but outputs argument's type with WXUNUSED:
#define _WX_VARARG_ARG_UNUSED(i)        T##i WXUNUSED(a##i)

// Generates code snippet for i-th type in vararg function's template<...>:
#define _WX_VARARG_TEMPL(i)             typename T##i

// Generates code snippet for passing i-th argument of vararg function
// wrapper to its implementation, normalizing it in the process:
#define _WX_VARARG_PASS_WCHAR(i) \
    wxArgNormalizerWchar<T##i>(a##i, fmt, i).get()
#define _WX_VARARG_PASS_UTF8(i) \
    wxArgNormalizerUtf8<T##i>(a##i, fmt, i).get()


// And the same for fixed arguments, _not_ normalizing it:
#define _WX_VARARG_PASS_FIXED(i)        f##i

#define _WX_VARARG_FIND_FMT(i) \
            (wxFormatStringArgumentFinder<TF##i>::find(f##i))

#define _WX_VARARG_FORMAT_STRING(numfixed, fixed)                             \
    _WX_VARARG_FIXED_TYPEDEFS(numfixed, fixed);                               \
    const wxFormatString *fmt =                                               \
            (_WX_VARARG_JOIN(numfixed, _WX_VARARG_FIND_FMT))

#if wxUSE_UNICODE_UTF8
    #define _WX_VARARG_DO_CALL_UTF8(return_kw, impl, implUtf8, N, numfixed)   \
        return_kw implUtf8(_WX_VARARG_JOIN(numfixed, _WX_VARARG_PASS_FIXED),  \
                        _WX_VARARG_JOIN(N, _WX_VARARG_PASS_UTF8))
    #define _WX_VARARG_DO_CALL0_UTF8(return_kw, impl, implUtf8, numfixed)     \
        return_kw implUtf8(_WX_VARARG_JOIN(numfixed, _WX_VARARG_PASS_FIXED))
#endif // wxUSE_UNICODE_UTF8

#define _WX_VARARG_DO_CALL_WCHAR(return_kw, impl, implUtf8, N, numfixed)      \
    return_kw impl(_WX_VARARG_JOIN(numfixed, _WX_VARARG_PASS_FIXED),          \
                    _WX_VARARG_JOIN(N, _WX_VARARG_PASS_WCHAR))
#define _WX_VARARG_DO_CALL0_WCHAR(return_kw, impl, implUtf8, numfixed)        \
    return_kw impl(_WX_VARARG_JOIN(numfixed, _WX_VARARG_PASS_FIXED))

#if wxUSE_UNICODE_UTF8
    #if wxUSE_UTF8_LOCALE_ONLY
        #define _WX_VARARG_DO_CALL _WX_VARARG_DO_CALL_UTF8
        #define _WX_VARARG_DO_CALL0 _WX_VARARG_DO_CALL0_UTF8
    #else // possibly non-UTF8 locales
        #define _WX_VARARG_DO_CALL(return_kw, impl, implUtf8, N, numfixed)    \
            if ( wxLocaleIsUtf8 )                                             \
              _WX_VARARG_DO_CALL_UTF8(return_kw, impl, implUtf8, N, numfixed);\
            else                                                              \
              _WX_VARARG_DO_CALL_WCHAR(return_kw, impl, implUtf8, N, numfixed)

        #define _WX_VARARG_DO_CALL0(return_kw, impl, implUtf8, numfixed)      \
            if ( wxLocaleIsUtf8 )                                             \
              _WX_VARARG_DO_CALL0_UTF8(return_kw, impl, implUtf8, numfixed);  \
            else                                                              \
              _WX_VARARG_DO_CALL0_WCHAR(return_kw, impl, implUtf8, numfixed)
    #endif // wxUSE_UTF8_LOCALE_ONLY or not
#else // wxUSE_UNICODE_WCHAR
    #define _WX_VARARG_DO_CALL _WX_VARARG_DO_CALL_WCHAR
    #define _WX_VARARG_DO_CALL0 _WX_VARARG_DO_CALL0_WCHAR
#endif // wxUSE_UNICODE_UTF8 / wxUSE_UNICODE_WCHAR


// Macro to be used with _WX_VARARG_ITER in the implementation of
// WX_DEFINE_VARARG_FUNC (see its documentation for the meaning of arguments)
#define _WX_VARARG_DEFINE_FUNC(N, rettype, name,                              \
                               impl, implUtf8, numfixed, fixed)               \
    template<_WX_VARARG_JOIN(N, _WX_VARARG_TEMPL)>                            \
    rettype name(_WX_VARARG_FIXED_EXPAND(numfixed, fixed),                    \
                 _WX_VARARG_JOIN(N, _WX_VARARG_ARG))                          \
    {                                                                         \
        _WX_VARARG_FORMAT_STRING(numfixed, fixed);                            \
        _WX_VARARG_DO_CALL(return, impl, implUtf8, N, numfixed);              \
    }

#define _WX_VARARG_DEFINE_FUNC_N0(rettype, name,                              \
                                  impl, implUtf8, numfixed, fixed)            \
    inline rettype name(_WX_VARARG_FIXED_EXPAND(numfixed, fixed))             \
    {                                                                         \
        _WX_VARARG_DO_CALL0(return, impl, implUtf8, numfixed);                \
    }

// Macro to be used with _WX_VARARG_ITER in the implementation of
// WX_DEFINE_VARARG_FUNC_VOID (see its documentation for the meaning of
// arguments; rettype is ignored and is used only to satisfy _WX_VARARG_ITER's
// requirements).
#define _WX_VARARG_DEFINE_FUNC_VOID(N, rettype, name,                         \
                                    impl, implUtf8, numfixed, fixed)          \
    template<_WX_VARARG_JOIN(N, _WX_VARARG_TEMPL)>                            \
    void name(_WX_VARARG_FIXED_EXPAND(numfixed, fixed),                       \
                 _WX_VARARG_JOIN(N, _WX_VARARG_ARG))                          \
    {                                                                         \
        _WX_VARARG_FORMAT_STRING(numfixed, fixed);                            \
        _WX_VARARG_DO_CALL(wxEMPTY_PARAMETER_VALUE,                           \
                           impl, implUtf8, N, numfixed);                      \
    }

#define _WX_VARARG_DEFINE_FUNC_VOID_N0(name, impl, implUtf8, numfixed, fixed) \
    inline void name(_WX_VARARG_FIXED_EXPAND(numfixed, fixed))                \
    {                                                                         \
        _WX_VARARG_DO_CALL0(wxEMPTY_PARAMETER_VALUE,                          \
                            impl, implUtf8, numfixed);                        \
    }

// Macro to be used with _WX_VARARG_ITER in the implementation of
// WX_DEFINE_VARARG_FUNC_CTOR (see its documentation for the meaning of
// arguments; rettype is ignored and is used only to satisfy _WX_VARARG_ITER's
// requirements).
#define _WX_VARARG_DEFINE_FUNC_CTOR(N, rettype, name,                         \
                                    impl, implUtf8, numfixed, fixed)          \
    template<_WX_VARARG_JOIN(N, _WX_VARARG_TEMPL)>                            \
    name(_WX_VARARG_FIXED_EXPAND(numfixed, fixed),                            \
                _WX_VARARG_JOIN(N, _WX_VARARG_ARG))                           \
    {                                                                         \
        _WX_VARARG_FORMAT_STRING(numfixed, fixed);                            \
        _WX_VARARG_DO_CALL(wxEMPTY_PARAMETER_VALUE,                           \
                           impl, implUtf8, N, numfixed);                      \
    }

#define _WX_VARARG_DEFINE_FUNC_CTOR_N0(name, impl, implUtf8, numfixed, fixed) \
    inline name(_WX_VARARG_FIXED_EXPAND(numfixed, fixed))                     \
    {                                                                         \
        _WX_VARARG_DO_CALL0(wxEMPTY_PARAMETER_VALUE,                          \
                            impl, implUtf8, numfixed);                        \
    }

// Macro to be used with _WX_VARARG_ITER in the implementation of
// WX_DEFINE_VARARG_FUNC_NOP, i.e. empty stub for a disabled vararg function.
// The rettype and impl arguments are ignored.
#define _WX_VARARG_DEFINE_FUNC_NOP(N, rettype, name,                          \
                                   impl, implUtf8, numfixed, fixed)           \
    template<_WX_VARARG_JOIN(N, _WX_VARARG_TEMPL)>                            \
    void name(_WX_VARARG_FIXED_UNUSED_EXPAND(numfixed, fixed),                \
                 _WX_VARARG_JOIN(N, _WX_VARARG_ARG_UNUSED))                   \
    {}

#define _WX_VARARG_DEFINE_FUNC_NOP_N0(name, numfixed, fixed)                  \
    inline void name(_WX_VARARG_FIXED_UNUSED_EXPAND(numfixed, fixed))         \
    {}

wxGCC_WARNING_RESTORE(ctor-dtor-privacy)

#endif // _WX_STRVARARG_H_
