What is an inline function

Inline functions are a programming language feature that tells the compiler to insert the function's code at the call point when the function is called, rather than executing it through a function call. The purpose of inline functions is to improve program execution efficiency and reduce the cost of function calls. The use of inline functions requires a trade-off between code size and execution efficiency. Although inline functions can improve the execution efficiency of the program, they will also increase the size of the code. If the code of the inline function is longer, the size of the program will increase. It may affect the cache hit rate, thereby reducing the execution efficiency of the program.