Is it possible to use std::string in a constexpr?

c++11 stdstring constexpr
Vector picture Vector · Nov 25, 2014 · Viewed 111k times · Source

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 use a character string in a constexpr?

Answer

Joseph Thomson picture Joseph Thomson · Apr 11, 2017

As of C++20, yes.

As of C++17, you can use string_view:

constexpr std::string_view sv = "hello, world";

A string_view is a string-like object that acts as an immutable, non-owning reference to any sequence of char objects.

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