Does the compiler decide when to inline my functions (in C++)?

Question

I understand you can use the inline keyword or just put a method in a class declaration ala short ctor or a getter method, but does the compiler make the final decision on when to inline my methods?

For instance:

inline void Foo::vLongBar()
{
   //several function calls and lines of code
}

Will the compiler ignore my inline declaration if it thinks it will make my code inefficient?

As a side issue, if I have a getter method declared outside my class like this:

void Foo::bar() { std::cout << "baz"; }

Will the compiler inline this under the covers?

Answer 1

Yes, the final decision of whether or not to inline your code lies in the C++ compiler. The inline keyword is a suggestion, not a requirement.

Here are some details as to how this decision is processed in the Microsoft C++ Compiler

• http://msdn.microsoft.com/en-us/library/z8y1yy88.aspx