TestFmt.cpp

#include <fmt/core.h>


#if __has_include(<source_location>)
#include <source_location>
#elif __has_include(<experimental/source_location>)
#include <experimental/source_location>
#else
#include "source_location.hpp"
#endif

#ifndef NOSTD_SOURCE_LOCATION_HPP
using sl = std::experimental::source_location;
#else
using sl = nostd::source_location;
#endif

template<typename Char, typename... TArgs>
struct BasicFmtStrSrcLoc : public fmt::basic_format_string<Char, TArgs...> {
    using ParentType = fmt::basic_format_string<Char, TArgs...>;
    sl sourceLocation;

    template <typename S>
    requires (std::is_convertible_v<const S&, fmt::basic_string_view<Char>>)
    consteval inline BasicFmtStrSrcLoc(const S& s, sl const& sourceL = sl::current()) : ParentType(s), sourceLocation(sourceL) {}

    BasicFmtStrSrcLoc(fmt::basic_runtime<Char> r, sl const& sourceL = sl::current()) : ParentType(r), sourceLocation(sourceL) {}
};

template <typename... Args>
using FmtStrSrcLoc = BasicFmtStrSrcLoc<char, fmt::type_identity_t<Args>...>;



namespace fmtlog {
    enum class LogLevel : uint8_t
    {
        DBG = 0,
        INF,
        WRN,
        ERR,
        OFF
    };
}

template<typename... TArgs>
constexpr static void fmtLogTest(FmtStrSrcLoc<TArgs...> str, TArgs&&... args) {
//            return fmtLogTag<lvl, TArgs...>(str, GLOBAL_TAG, std::forward<TArgs>(args)...);
}

template<fmtlog::LogLevel logLevel, typename... TArgs>
constexpr static void fmtLogTest2(FmtStrSrcLoc<TArgs...> str, TArgs&&... args) {
//            return fmtLogTag<lvl, TArgs...>(str, GLOBAL_TAG, std::forward<TArgs>(args)...);
}

namespace Paper {
    struct Logger {
        template<fmtlog::LogLevel logLevel, typename... TArgs>
        constexpr static void fmtLogTest3(fmt::format_string<TArgs...> str, TArgs&&... args) {
//            return fmtLogTag<lvl, TArgs...>(str, GLOBAL_TAG, std::forward<TArgs>(args)...);
        }

        template<fmtlog::LogLevel logLevel, typename... TArgs>
        constexpr static void fmtLogTest4(FmtStrSrcLoc<TArgs...> str, TArgs&&... args) {
//            return fmtLogTag<lvl, TArgs...>(str, GLOBAL_TAG, std::forward<TArgs>(args)...);
        }
    };
}

extern "C" void t() {
    // this compiles
    fmt::format_string<int> foo("foo! {}");

    FmtStrSrcLoc<int> bar("bar! {}");

    fmtLogTest("nonsense! {}", 5);
    fmtLogTest2<fmtlog::LogLevel::INF, int>("hi! {}", 5);
    Paper::Logger::fmtLogTest3<fmtlog::LogLevel::INF, int>("hi! {}", 5);

    // this does not
    Paper::Logger::fmtLogTest4<fmtlog::LogLevel::INF, int>("hi! {}", 5);
}