7.1.2 Function specifiers
2 A function declaration (8.3.5, 9.3, 11.4) with an inline specifier declares an inline function. The inline
specifier indicates to the implementation that inline substitution of the function body at the point of call
is to be preferred to the usual function call mechanism. An implementation is not required to perform this
inline substitution at the point of call; however, even if this inline substitution is omitted, the other rules
for inline functions defined by 7.1.2 shall still be respected.
3 A function defined within a class definition is an inline function. The inline specifier shall not appear on
a block scope function declaration.
87
If the inline specifier is used in a friend declaration, that declaration
shall be a definition or the function shall have previously been declared inline.
87) The inline keyword has no effect on the linkage of a function.
§ 7.1.2 137
c ISO/IEC N3035=10-0025
4 An inline function shall be defined in every translation unit in which it is used and shall have exactly
the same definition in every case (3.2). [ Note: a call to the inline function may be encountered before its
definition appears in the translation unit. — end note ] If the definition of a function appears in a translation
unit before its first declaration as inline, the program is ill-formed. If a function with external linkage is
declared inline in one translation unit, it shall be declared inline in all translation units in which it appears;
no diagnostic is required. An inline function with external linkage shall have the same address in all
translation units. A static local variable in an extern inline function always refers to the same object.
A string literal in the body of an extern inline function is the same object in different translation units.
[ Note: A string literal appearing in a default argument expression is not in the body of an inline function
merely because the expression is used in a function call from that inline function. — end note ]