19 struct ConstexprString {  struct
20   constexpr ConstexprString() : ConstexprString("") {}  in ConstexprString()  argument
21   constexpr ConstexprString(const char *p, std::size_t size) : data(new char[size+1]) {  in ConstexprString()  function
25   constexpr ConstexprString(const char *p) : ConstexprString(p, __builtin_strlen(p)) {}  in ConstexprString()  argument
26   constexpr explicit ConstexprString(const char *p, const char *q) : data(nullptr) {  in ConstexprString()  argument
33   constexpr ConstexprString(const ConstexprString &o) : ConstexprString(o.data) {}  in ConstexprString()  function
34   constexpr ConstexprString(ConstexprString &&o) : data(o.data) { o.data = nullptr; }  in ConstexprString()  function
35   constexpr ConstexprString &operator=(const ConstexprString &o) {  in operator =()  argument
38   constexpr ConstexprString &operator=(ConstexprString &&o) {  in operator =()  argument
44   constexpr ~ConstexprString() { delete[] data; }  in ~ConstexprString()  argument
47   friend constexpr ConstexprString operator+(const ConstexprString &a, const ConstexprString &b) {  in operator +()  argument