C++ typecasting when passing std::string as function argument

Question

Is passing a string by "" equivalent to passing a string by calling std::str("") in C++?

e.g. given a function which accepts std::str as an argument:

void funcA(std::string arg) {
    arg = "abc";
}

Should I call it by funcA(std::string("abc")); or funcA("abc"); ? i.e. is the second version a typecast from an array of char?

#5: en.cppreference.com/w/cpp/string/basic_string/basic_string — Qaz
– Qaz, Commented Apr 13, 2013 at 4:59
question is, is the second version's argument treated as an array of char instead? — jhtong
– jhtong, Commented Apr 13, 2013 at 5:00
@PabloLemurr Kind of. string and char [] are two very distinct data types, and although they represent the same concept (character strings), when discussing a question like this, the difference is not negligible. — user529758
– user529758, Commented Apr 13, 2013 at 5:07
@PabloLemurr An array in C++ is a data type containing a fixed number of objects of the same type. A std::string maintains a variable number of characters in a contiguous block of memory. Quite different, but same in terms of pointer arithmetic. — Potatoswatter
– Potatoswatter, Commented Apr 13, 2013 at 5:07

Potatoswatter · Accepted Answer · 2013-04-13 05:01:21Z

4

They are equivalent. Because the constructor std::string::string( char const * ) is not declared as explicit, it is called implicitly to provide a conversion from char * to string. The implicit call does the same thing as the explicit call (written out as std::string("abc")).

answered Apr 13, 2013 at 5:01

Potatoswatter

139k29 gold badges281 silver badges435 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

C++ typecasting when passing std::string as function argument

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related