Although the compiler doesn't have a separate preprocessor, the directives described in this section are processed as if there were one. You use them to help in conditional compilation. Unlike C and C++ directives, you can't use these directives to create macros. A preprocessor directive must ...
Although the compiler doesn't have a separate preprocessor, the directives described in this section are processed as if there were one. You use them to help in conditional compilation. Unlike C and C++ directives, you can't use these directives to create macros. A preprocessor directive must ...
The preprocessor directives instruct the compiler how to treat the source code. For example, under certain conditions, you might want the compiler to ignore portions of the code, and under other conditions, you might want that code compiled. The preprocessor directives give you those options and ...
The C preprocessor modifies a source file before handing it over to the compiler, allowing conditional compilation with #ifdef, defining constants with #define, including header files with #include, and using builtin macros such as __FILE__. This page lists the preprocessor directives, or ...
C-preprocessor directives v17 Suggest edits The ECPGPlus C-preprocessor enforces two behaviors that depend on the mode in which you invoke ECPGPlus: PROC mode Non-PROC mode Compiling in PROC mode In PROC mode, ECPGPlus allows you to:...
nothing, in this case the directive has no effect. a line break. Themodule and import directivesare also preprocessing directives. (since C++20) Preprocessing directives must not come from macro expansion. #define EMPTYEMPTY# include <file.h> // not a preprocessing directive ...
#define NAME"C:\ETC\DATA" #else /* DOS */ #define NAME"/etc/data" #endif /* DOS */ Actually, the#elseand#endifdirectives take no arguments. The following them is entirely a comment, but a necessary one. It serves to match#elseand#endifdirective with the initial#ifdef. ...
which would result in 1 * 5 being evaluated before the addition, not after. Oops! It is also possible to write simply #define [identifier name] which defines [identifier name] without giving it a value. This can be useful in conjunction with another set of directives that allow conditional...
This example shows how to add undefine preprocessor directives to a build information object. Suppose you have two files,myFile.candmyInc.h, in your current working folder. // myFile.c #include <stdio.h> int main(void) { #ifdef __STDC_VERSION__ printf("__STDC_VERSION__ is defined\n...
These directives will then be processed in order. For example, the following also behaves identically to the prior examples: Alex.h: #define MY_NAME "Alex" Copy main.cpp: #include "Alex.h" // copies #define MY_NAME from Alex.h here #include <iostream> int main() { std::cout << ...