'+' cannot add two pointers error

Question

I can do what the following code shows:

std::string a = \"chicken \";
std::string b = \"nuggets\";
std::string c = a + b;

However, this fails:<

Answer 1

"chicken " and "nuggets" are not of type std::string but are const char[]. As such even though you want to assign the concatenation to a string they types don't have an operator +. You could solve this using:

std::string c = std::string("chicken ") + "nuggets";

Answer 2

Both "chicken" and "nuggets" has type const char* (as literals in code). So you are trying to add to pointers.

Try std::string c = std::string("chicken") + "nuggets";

std::string is not part of language itself, it's a part of standard library. C++ aims to have as few language features as possible. So built-in type for strings is not present in parser etc. That's why string literals will be treaded as pointers.

EDIT

To be completely correct: type of literals is really const char[N] (where N is character count in literal +1 for \0. But in C++ arrays ([]) can be treated as pointers, and that is what compiler tries to do (as it cannot add arrays)

Answer 3

"chicken " and "nuggets" are literal C-string and not std::string.

You may concatenate directly with:

std::string c = "chicken " "nuggets";

Since C++14, you may add suffix s to have string

using namespace std::string_literals;
std::string c = "chicken "s + "nuggets"s;