I want to have fmt::format return a wstring from EA's STL, but when I try to modify this code from the docs—which works fine:
// Prints formatted error message.
void
vreport_error(const char *format, fmt::format_args args) {
fmt::print("Error: ");
fmt::vprint(format, args);
}
template <typename... Args>
void
report_error(const char *format, const Args &... args) {
vreport_error(format, fmt::make_format_args(args...));
}
to use wchar_t instead of char:
// Prints formatted error message.
void vreport_error2(const wchar_t *format, fmt::format_args args);
template <typename... Args>
void
report_error2(const wchar_t *format, const Args &... args) {
vreport_error2(format, fmt::make_format_args(args...));
}
I get:
2>fmt\core.h(1219,1): error C2665: 'fmt::v5::basic_format_args<fmt::v5::wformat_context>::basic_format_args': none of the 4 overloads could convert all the argument types
2>fmt\core.h(1219,1): error C2665: : basic_format_args<wformat_context>(std::forward<Args>(args)...) {}
2>fmt\core.h(1219,1): error C2665: ^ (compiling source file ..\core\typedefs.cpp)
2>fmt\core.h(1207,1): message : could be 'fmt::v5::basic_format_args<fmt::v5::wformat_context>::basic_format_args(fmt::v5::basic_format_args<fmt::v5::wformat_context> &&)'
2>fmt\core.h(1207,1): message : };
2>fmt\core.h(1207,1): message : ^ (compiling source file ..\core\typedefs.cpp)
2>fmt\core.h(1207,1): message : or 'fmt::v5::basic_format_args<fmt::v5::wformat_context>::basic_format_args(const fmt::v5::basic_format_args<fmt::v5::wformat_context> &)'
2>fmt\core.h(1207,1): message : };
2>fmt\core.h(1207,1): message : ^ (compiling source file ..\core\typedefs.cpp)
2>fmt\core.h(1189,3): message : or 'fmt::v5::basic_format_args<fmt::v5::wformat_context>::basic_format_args(const fmt::v5::basic_format_arg<Context> *,int)'
2>fmt\core.h(1189,3): message : with
2>fmt\core.h(1189,3): message : [
2>fmt\core.h(1189,3): message : Context=fmt::v5::wformat_context
2>fmt\core.h(1189,3): message : ]
2>fmt\core.h(1189,3): message : basic_format_args(const format_arg* args, int count)
2>fmt\core.h(1189,3): message : ^ (compiling source file ..\core\typedefs.cpp)
2>fmt\core.h(1171,3): message : or 'fmt::v5::basic_format_args<fmt::v5::wformat_context>::basic_format_args(void)'
2>fmt\core.h(1171,3): message : basic_format_args() : types_(0) {}
2>fmt\core.h(1171,3): message : ^ (compiling source file ..\core\typedefs.cpp)
2>fmt\core.h(1219,1): message : while trying to match the argument list '(fmt::v5::format_args)'
2>fmt\core.h(1219,1): message : : basic_format_args<wformat_context>(std::forward<Args>(args)...) {}
2>fmt\core.h(1219,1): message : ^ (compiling source file ..\core\typedefs.cpp)
Alternatively if I try to convert into char and then convert out, I can't get it to work for more than one argument:
wstring
fmt_msg2(const wchar_t *msg, fmt::format_args args) {
std::string s = utf8_from_utf16(msg).c_str();
std::string s_ = fmt::vformat(s, args);
return utf16_from_utf8(s_.data());
}
wstring s = fmt_msg2(L"hey {}", 24); // works
wstring s = fmt_msg2(L"hey {} {}", 24, 58); // error
1>client.cpp
1>client.cpp(757,44): error C2660: 'fmt_msg2': function does not take 3 arguments
1>client.cpp(757,44): error C2660: wstring s = fmt_msg2(L"hey {} {}", 24, 58);
1>client.cpp(757,44): error C2660: ^
1>typedefs.h(109,9): message : see declaration of 'fmt_msg2'
1>typedefs.h(109,9): message : wstring fmt_msg2(wchar_t cc *msg, fmt::format_args args);
1>typedefs.h(109,9): message : ^
I also found mention of a fmt::MemoryWriter which might help me format into a wchar_t[], but it looks like it isn't available anymore?
Not sure what else to try.
update
After looking at it with fresh eyes, I realized that I wasn't wrapping fmt_msg2—and so now I have this:
in the typedefs.h file:
ea::wstring vfmt_msg3(const ea::wstring &msg, fmt::wformat_args args);
template <typename... Args>
ea::wstring
fmt_msg3(const ea::wstring &format, const Args &... args) {
return vfmt_msg3(format, fmt::make_format_args<fmt::wformat_args>(args...));
}
in the client.cpp file:
ea::wstring
vfmt_msg3(const ea::wstring &msg, fmt::wformat_args args) {
std::wstring s_ = fmt::vformat(std::wstring(msg.data()), args);
return ea::wstring(s_.data());
}
wstring s = fmt_msg3(L"hey {} {}", 24, 58);
But on Visual Studio 16.2.0 I get the following error:
core.h(687,39): error C2039: 'char_type': is not a member of 'fmt::v5::wformat_args'
core.h(687,39): error C2039: using char_type = typename Context::char_type;
core.h(687,39): error C2039: ^ (compiling source file client.cpp)
core.h(1216): message : see declaration of 'fmt::v5::wformat_args'
core.h(1216): message : struct wformat_args : basic_format_args<wformat_context> { (compiling source file client.cpp)
core.h(1095): message : see reference to class template instantiation 'fmt::v5::internal::value<Context>' being compiled
core.h(1095): message : with
core.h(1095): message : [
core.h(1095): message : Context=fmt::v5::wformat_args
core.h(1095): message : ]
core.h(1095): message : value_type data_[num_args + (!is_packed || num_args == 0 ? 1 : 0)]; (compiling source file client.cpp)
typedefs.h(119): message : see reference to class template instantiation 'fmt::v5::format_arg_store<fmt::v5::wformat_args,int,int>' being compiled
typedefs.h(119): message : fmt_msg3(const ea::wstring &format, const Args &... args) { (compiling source file client.cpp)
client.cpp(757): message : see reference to function template instantiation 'eastl::wstring fmt_msg3<int,int>(const eastl::wstring &,const int &,const int &)' being compiled
client.cpp(757): message : wstring s = fmt_msg3(L"hey {} {}", 24, 58);