How can you compare two character strings statically at compile time
You can do this with C++11 by using a constexpr function:
constexpr bool strings_equal(char const * a, char const * b) { return *a == *b && (*a == '\0' || strings_equal(a + 1, b + 1));}It's not possible to do this prior to C++11, with the caveat that many compilers will compile equal string literals to be a pointer to the same location. On these compilers it's sufficient to compare the strings directly since they will both be evaluated as equal pointers.
Starting with C++17 std::string_view is available. It supports constexpr comparisson:
#include <string_view>constexpr bool strings_equal(char const * a, char const * b) { return std::string_view(a)==b;}int main() { static_assert(strings_equal("abc", "abc" ), "strings are equal"); static_assert(!strings_equal("abc", "abcd"), "strings are not equal"); return 0;}