How to define a type conversion from std::string to a custom type?

Question

Conversion operators are declared inside a class like this:

operator string();

When declared, they can be defined like this;

Foo::operator string(){ return stringRep; }

How can I define a conversion operator from string to my custom type?

Answer 1

编写一个接受字符串的构造函数。

Answer 2

A conversion operator/function operator Tc , of a Class of type Ty is a non static member function which converts the Type Ty to some specified type.

If you need to convert from string, which is a Class of type std::basic_string<char> to a Type of Tc , either

1. std::basic_string , needs to provide a Type conversion function, or
2. you need to provide a constructor in the Class of Type Tc that accepts an object of type std::basic_string<char> .