src/chapter0/lesson13/standard.cpp


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// This program prints the C++ language standard your compiler is currently
// using

#include <iostream>

const int numStandards = 7;

const long stdCode[numStandards] = {199711L, 201103L, 201402L, 201703L,
                                    202002L, 202302L, 202612L};
const char *stdName[numStandards] = {"Pre-C++11", "C++11", "C++14", "C++17",
                                     "C++20",     "C++23", "C++26"};

long getCPPStandard() {
#if defined(_MSVC_LANG)
  return _MSVC_LANG;
#elif defined(_MSC_VER)
  return -1;
#else
  return __cplusplus;
#endif
}

int main() {
  long standard = getCPPStandard();

  if (standard == -1) {
    std::cout << "Error: Unable to determine your language standard.\n";
    return 0;
  }

  for (int i = 0; i < numStandards; ++i) {
    // If the reported version is one of the finalized standard
    // codes then we know exactly what version the compiler is
    // running
    if (standard == stdCode[i]) {
      std::cout << "Your compiler is using " << stdName[i]
                << " (language standard code " << standard << "L)\n";
      break;
    }
  }

  return 0;
}