Editing Inline function (section)

== Restrictions ==
Taking the address of an <code>inline</code> function requires code for a non-inlined copy of that function to be emitted in any case.

In C99, an <code>inline</code> or <code>extern inline</code> function must not access <code>static</code> global variables or define non-<code>const</code> <code>static</code> local variables. <code>const static</code> local variables may or may not be different objects in different translation units, depending on whether the function was inlined or whether a call was made. Only <code>static inline</code> definitions can reference identifiers with internal linkage without restrictions; those will be different objects in each translation unit. In C++, both <code>const</code> and non-<code>const</code> <code>static</code> locals are allowed and they refer to the same object in all translation units.

gcc cannot inline functions if<ref name="gcc-inline"/>
# they are [[variadic function|variadic]],
# use <code>[[alloca]]</code>
# use computed <code>goto</code>
# use nonlocal <code>goto</code>
# use [[nested function]]s
# use <code>setjmp</code>
# use <code>__builtin_longjmp</code>
# use <code>__builtin_return</code>, or
# use <code>__builtin_apply_args</code>

Based on Microsoft Specifications at MSDN, MS Visual C++ cannot inline (not even with <code>__forceinline</code>), if

# The function or its caller is compiled with /Ob0 (the default option for debug builds).
# The function and the caller use different types of [[exception handling]] (C++ exception handling in one, structured exception handling in the other).
# The function has a [[variable argument list]].
# The function uses [[inline assembly]], unless compiled with /Og, /Ox, /O1, or /O2.
# The function is [[Recursion (computer science)|recursive]] and not accompanied by <code>#pragma inline_recursion(on)</code>. With the pragma, recursive functions are inlined to a default depth of 16 calls. To reduce the inlining depth, use <code>inline_depth</code> pragma.
# The function is [[virtual function|virtual]] and is called virtually. Direct calls to virtual functions can be inlined.
# The program takes the address of the function and the call is made via the pointer to the function. Direct calls to functions that have had their address taken can be inlined.
# The function is also marked with the naked <code>__declspec</code> modifier.