7.9.15 The FUNC_IS_PURE Pragma

The FUNC_IS_PURE pragma specifies to the compiler that the named function has no side effects. This allows the compiler to do the following:

Delete the call to the function if the function's value is not needed
Delete duplicate functions

The pragma must appear before any declaration or reference to the function. In C, the argument func is the name of a function. In C++, the pragma applies to the next function declared.

The syntax of the pragma in C is:

#pragma FUNC_IS_PURE (func)

The syntax of the pragma in C++ is:

#pragma FUNC_IS_PURE