How to determine the version of the C++ standard used by the compiler?
Sometimes we need to know that, what is the current C++ standard. To get this kind of information, we can use the macro called __cplusplus. For different standards, the value of this will be like below.
| Standard | __cplusplus output |
|---|
C++ pre C++98
| 1 |
C++98
| 199711L |
C++98 + TR1
| This cannot be checked, this will be marked as C++98 |
C++11
| 201103L |
C++14
| 201402L |
C++17
| 201703L |
Example
#include<iostream>
int main() {
if (__cplusplus == 201703L)
std::cout << "C++17" << endl;
else if (__cplusplus == 201402L)
std::cout << "C++14" << endl;
else if (__cplusplus == 201103L)
std::cout << "C++11" << endl;
else if (__cplusplus == 199711L)
std::cout << "C++98" << endl;
else
std::cout << "pre-standard C++" << endl;
}Output
C++98
Published on 03-May-2019 10:35:37
