C++ 字符串字面量和常量

Question

Before asking this, I read previous question , but the issue is a bit different. I'm using this in my class:

static constexpr char* kSuffix = "tos";

Compiling with gcc with c++11 got me this error:

error: ISO C++ forbids converting a string constant to 'char*' [-Werror=write-strings]

But constexpr is a stricter constraint than const does, so a constexpr is must a const , but not vice versa. So I wonder why is gcc not recognising constexpr in this case?

Answer 1

so a constexpr is must a const

Note that the constexpr is qualified on kSuffix itself, so the pointer becomes const (as char* const ), but the pointee won't become const (as const char* ). Gcc just wants to tell you that you should declare kSuffix as a pointer to const , ie

static constexpr const char* kSuffix = "tos";