nameof_module/nameof.cpp

// MIT License
//
// Copyright(c) 2016 - 2018 Terik23
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files(the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions :
//
// The above copyright notice and this permission notice shall be included in
// all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

inline constexpr const char* template_nameof_(const char* name, size_t length) {
  return length == 0 ? name
                     : (name[length - 1] == '.' || name[length - 1] == '>' || name[length - 1] == ':')
                           ? &name[length]
                           : template_nameof_(name, length - 1);
}

// Used to obtain the string name of a variable.
#define nameof_variable(variable) template_nameof_variable(variable, #variable, sizeof(#variable) / sizeof(char) - 1)
template <typename T>
inline constexpr const char* template_nameof_variable(const T& validate_type, const char* name, size_t length) { return template_nameof_(name, length); }

// Used to obtain the string name of a type.
#define nameof_type(type) template_nameof_type<type>(#type)
template <typename T> inline constexpr const char* template_nameof_type(const char* name) { return name; }

// Used to obtain the string name of a function.
#define nameof_function(function) template_nameof_function(#function, sizeof(#function) / sizeof(char) - 1); if (false) (void)(function);
inline constexpr const char* template_nameof_function(const char* name, size_t length) { return template_nameof_(name, length); }

// Example.
#include <iostream>

struct SomeStruct {
  int SomeField;
  void SomeMethod() { std::cout << "No called!" << std::endl; }
};

int someVar = 0;

int main() {
  SomeStruct someVar{1};

  constexpr auto a = nameof_variable(someVar.SomeField);
  constexpr auto b = nameof_variable((&someVar)->SomeField);
  constexpr auto c = nameof_variable(someVar);
  constexpr auto d = nameof_variable(::someVar);
  constexpr auto e = nameof_variable(&SomeStruct::SomeMethod);
  constexpr auto f = nameof_function(someVar.SomeMethod());
  constexpr auto g = nameof_type(SomeStruct);

  std::cout << a << std::endl;  // SomeField
  std::cout << b << std::endl;  // SomeField
  std::cout << c << std::endl;  // someVar
  std::cout << d << std::endl;  // someVar
  std::cout << e << std::endl;  // SomeMethod
  std::cout << f << std::endl;  // SomeMethod()
  std::cout << g << std::endl;  // SomeStruct
}