I want to have a static const char array in my class. GCC complained and told me I should use constexpr, although now it’s telling me it’s an undefined reference. If I make the array a non-member then it compiles. What is going on? // .hpp struct foo { void bar(); static constexpr char baz[] … Read more
Using C++11, Ubuntu 14.04, GCC default toolchain. This code fails: constexpr std::string constString = “constString”; error: the type ‘const string {aka const std::basic_string}’ of constexpr variable ‘constString’ is not literal… because… ‘std::basic_string’ has a non-trivial destructor Is it possible to use std::string in aconstexpr? (apparently not…) If so, how? Is there an alternative way to … Read more
If I have a variable inside a function (say, a large array), does it make sense to declare it both static and constexpr? constexpr guarantees that the array is created at compile time, so would the static be useless? void f() { static constexpr int x [] = { // a few thousand elements }; … Read more
It seems to me that having a “function that always returns 5” is breaking or diluting the meaning of “calling a function”. There must be a reason, or a need for this capability or it wouldn’t be in C++11. Why is it there? // preprocessor. #define MEANING_OF_LIFE 42 // constants: const int MeaningOfLife = 42; … Read more
Is there a difference between the following definitions? const double PI = 3.141592653589793; constexpr double PI = 3.141592653589793; If not, which style is preferred in C++11? 5 Answers 5
What’s the difference between constexpr and const? When can I use only one of them? When can I use both and how should I choose one? 10 s 10 Basic meaning and syntax Both keywords can be used in the declaration of objects as well as functions. The basic difference when applied to objects is … Read more
