void Foo1(string_view view) {
...
}
string str = "one two three";
Foo1("one two three"); // Implicitly convert char* to string_view
Foo1(str);
I wonder which constructor converts char* to string_view implicitly and which one converts the string to string_view implicitly?
I know constructor (4) convert const char* to string_view but what I passed is char*.
std::string_view has a non-explicit converting constructor taking const char*, which supports implicit conversion from const char* to std::string_view.
constexpr basic_string_view(const CharT* s);
When you say:
but what I passed is
char*.
You're actually passing a string literal (i.e. "one two three"), whose type is const char[14] (including the null terminator '\0'), which could decay to const char*.
And std::string has a non-explicit conversion operator which supports implicit conversion from std::string to std::string_view.
constexpr operator std::basic_string_view<CharT, Traits>() const noexcept;
It's https://en.cppreference.com/w/cpp/string/basic_string/operator_basic_string_view:
together with string_view's copy constructor (2)