--- description: "Learn more about the function pragma directive in Microsoft C/C++" title: "function pragma" ms.date: 01/22/2021 f1_keywords: ["function_CPP", "vc-pragma.function"] helpviewer_keywords: ["function pragma", "pragma, function"] no-loc: ["pragma"] --- # `function` pragma Tells the compiler to generate calls to functions specified in the pragma's argument list, instead of inlining them. ## Syntax > **`#pragma function(`** *function1* [ **`,`** *function2* ... ] **`)`** ## Remarks Intrinsic functions are normally generated as inline code, not as function calls. If you use the [`intrinsic` pragma](intrinsic.md) or the [`/Oi`](../build/reference/oi-generate-intrinsic-functions.md) compiler option to tell the compiler to generate intrinsic functions, you can use the **`function`** pragma to explicitly force a function call. Once a **`function`** pragma is seen, it takes effect at the first function definition that contains a specified intrinsic function. The effect continues to the end of the source file, or to the appearance of an `intrinsic` pragma specifying the same intrinsic function. You can only use the **`function`** pragma outside of a function, at the global level. For lists of the functions that have intrinsic forms, see [`intrinsic` pragma](intrinsic.md). ## Example ```cpp // pragma_directive_function.cpp #include #include #include #include // use intrinsic forms of memset and strlen #pragma intrinsic(memset, strlen) // Find first word break in string, and set remaining // chars in string to specified char value. char *set_str_after_word(char *string, char ch) { int i; int len = strlen(string); /* NOTE: uses intrinsic for strlen */ for(i = 0; i < len; i++) { if (isspace(*(string + i))) break; } for(; i < len; i++) *(string + i) = ch; return string; } // do not use strlen intrinsic #pragma function(strlen) // Set all chars in string to specified char value. char *set_str(char *string, char ch) { // Uses intrinsic for memset, but calls strlen library function return (char *) memset(string, ch, strlen(string)); } int main() { char *str = (char *) malloc(20 * sizeof(char)); strcpy_s(str, sizeof("Now is the time"), "Now is the time"); printf("str is '%s'\n", set_str_after_word(str, '*')); printf("str is '%s'\n", set_str(str, '!')); } ``` ```Output str is 'Now************' str is '!!!!!!!!!!!!!!!' ``` ## See also [Pragma directives and the `__pragma` and `_Pragma` keywords](./pragma-directives-and-the-pragma-keyword.md)