Question

I have a line of code that seems to convert a char array to a string

foobar(string("text")+anotherString);

foobar expects a std::string as an argument

I’ve never seen a conversion done this way… what function is being called on “text”. or is it some tricky way of casting?

Answer 1

std::string has a constructor that takes a char-array* (assumed null-terminated), which I’m sure you have seen before:

std::string s1 = "hello world";
std::string s2("also hello world");  // "same thing", essentially

So std::string("test") just creates a temporary string object with value "test".

Furthermore, there’s a free operator+ for string and const char * which appends the data in the char-array (again assumed null-terminated) to the string.

Equivalently you can write std::string("test").append(anotherString), for the same effect (i.e. a temporary containing the two strings, concatenated).

For a list of operations supported by std::string, consult any decent manual.

_{*) or rather, “a pointer to the first element of an array of chars”}