type_name.h

Go to the documentation of this file.

 
#ifndef GUL17_TYPE_NAME_H_
#define GUL17_TYPE_NAME_H_
 
#include <string_view>
 
#include "gul17/internal.h"
 
namespace gul17 {
 
template <typename T>
class FailToInstantiate;
 
template <class T>
constexpr std::string_view type_name()
{
#if defined(__GNUC__)
    // Clang returns something like "return_type function_name() [T = template_parameter; ...]"
    // GCC returns something like "return_type function_name() [with T = template_parameter]"
    auto s = std::string_view{ static_cast<const char*>(__PRETTY_FUNCTION__) };
    auto const start_idx = s.find(" = ") + 3; // len(" = ") == 3
    s.remove_prefix(start_idx);
 
    auto const colon_idx = s.find(";");
    auto const suff_length =
        (colon_idx != std::string_view::npos) ? s.length() - colon_idx : 1; // len("]") == 1
    s.remove_suffix(suff_length);
    return s;
#elif defined(_MSC_VER)
    // MSVC returns something like "return_type function_name<template_parameter>()"
    auto s = std::string_view{ __FUNCSIG__ };
    auto const start_idx = s.find("gul17::type_name<") + sizeof("gul17::type_name<") - 1;
    s.remove_prefix(start_idx);
 
    for (auto end_idx = s.length() - 1; end_idx; --end_idx) {
        if (s[end_idx] != '>')
            continue;
        s.remove_suffix(s.length() - end_idx);
        break;
    }
    return s;
#else
    return "";
#endif
}
 
 
} // namespace gul17
 
#endif
 
// vi:ts=4:sw=4:et:sts=4