# Extra Clang Tools 18.1.8 documentation

## clang-tidy - performance-move-const-arg

# performance-move-const-arg

The check warns

- if `std::move()` is called with a constant argument,

- if `std::move()` is called with an argument of a trivially-copyable type,

- if the result of `std::move()` is passed as a const reference argument.

In all three cases, the check will suggest a fix that removes the `std::move()`.

Here are examples of each of the three cases:

    const string s;
    return std::move(s);  // Warning: std::move of the const variable has no effect

    int x;
    return std::move(x);  // Warning: std::move of the variable of a trivially-copyable type has no effect

    void f(const string &s);
    string s;
    f(std::move(s));  // Warning: passing result of std::move as a const reference argument; no move will actually happen

## Options

CheckTriviallyCopyableMove

  If true, enables detection of trivially copyable types that do not have a move constructor. Default is true.

CheckMoveToConstRef

  If true, enables detection of std::move() passed as a const reference argument. Default is true.