Con.5:对于可以在编译时计算的值,使用constexpr进行声明
Better performance, better compile-time checking, guaranteed compile-time evaluation, no possibility of race conditions.
更好的性能,更好的编译检查,保证编译时计算,不存在竞争条件。
Example(示例)
double x = f(2); // possible run-time evaluation
const double y = f(2); // possible run-time evaluation
constexpr double z = f(2); // error unless f(2) can be evaluated at compile time
See F.4.
参见:F.4
Enforcement(实施建议)
原文链接
https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#con5-use-constexpr-for-values-that-can-be-computed-at-compile-time