Описание тега preprocessor-directive
Instructions to a preprocessor that control how it modifies source text
The C and C++ preprocessors recognise directives such as #include and #define, part of the C language syntax, which control how the preprocessor modifies the source text.
The C and C++ preprocessors use the following directives:
- source file inclusion:
#include - macro definition:
#define,#undef - conditional inclusions:
#if,#elif,#ifdef,#ifndef,#elseand#endif - diagnostic messages:
#error(and as a common non-standard extension,#warning) - implementation-defined details:
#pragma - operators:
#,##,definedand_Pragma