On inline function

What is an inline function

In Baidu Encyclopedia " In computer science , Inline function （ Sometimes called online functions or compile time expansion functions ） Is a programming language structure , It is used to suggest the compiler to extend some special functions inline （ Sometimes called online expansion ）". The key word here is compiler , The behavior occurs in the compilation phase rather than the program running phase , So you used inline Syntax , It will increase the running time of your program, but it will not change the architecture and results of your program .

Motivation for designing inline functions

The inline function is C++ One of the enhanced features of . Inline extensions are used to eliminate the inherent time consumption caused by calling functions , Be able to execute functions quickly , This method also has spatial benefits for very small functions . Inline functions allow programmers to control the frequency of functions , Give the compiler favorable advice on whether the function is inline , Of course, if the function body is very large , The compiler also ignores the inline life of functions , I won't take your advice .

Syntax of inline functions

stay C++ The syntax keyword in the inline is "inline", Decorate... At the beginning of the function , You can say function inline declaration .

Comparison of inline functions and macros

• Macros use text substitution , May not lead to expected consequences , Because of the priority of symbols , Calculate the parameters , Error in operation sequence .

• Macro calls do not perform type checking , Function calls need to be checked

• Macro compilation errors in compilation are difficult to find