+ works for string literal also

[qazmlp]

int main()
{
std::string strVal = "2" ;
strVal = "000" + strVal ;
}

I am wondering how the above one compiles well. I expected that, it should be

int main()
{
std::string strVal = "2" ;
strVal = std::string("000") + strVal ;
}

 

[Ron Natalie]

int main()
{
std::string strVal = "2" ;
strVal = "000" + strVal ;
}

I am wondering how the above one compiles well. I expected that, it should be

An overload for operator+ is provided
string operator+(const char*, const string& )

(Not literally, but the above is good enough to understand the issue).

This means you can mix most operations you can do with strings with char*'s pointing
at null terminated strings as long as one operand is a string type (obviously no overload
is possible if both args are pointers).

"000" + str;
str + "000"
str + str;

are all valid

"000" + "000"

is not.