Search results
Results from the WOW.Com Content Network
The C preprocessor (used with C, C++ and in other contexts) defines an include directive as a line that starts #include and is followed by a file specification. COBOL defines an include directive indicated by copy in order to include a copybook. Generally, for C/C++ the include directive is used to include a header file, but can
In the C and C++ programming languages, an #include guard, sometimes called a macro guard, header guard or file guard, is a way to avoid the problem of double inclusion when dealing with the include directive.
Others are reduced to placeholders, such as (until C++20) <ciso646> for C95 <iso646.h>, all of whose requisite macros are rendered as keywords in C++98. C-specific syntactic constructs aren’t generally supported, even if their header is. [45] Several C headers exist primarily for C++ compatibility, and these tend to be near-empty in C++.
windows.h is a source code header file that Microsoft provides for the development of programs that access the Windows API (WinAPI) via C language syntax. It declares the WinAPI functions, associated data types and common macros. Access to WinAPI can be enabled for a C or C++ program by including it into a source file: #include <windows.h>
Using #pragma once allows the C preprocessor to include a header file when it is needed and to ignore an #include directive otherwise. This has the effect of altering the behavior of the C preprocessor itself, and allows programmers to express file dependencies in a simple fashion, obviating the need for manual management.
The C preprocessor is the macro preprocessor for several computer programming languages, such as C, Objective-C, C++, and a variety of Fortran languages. The preprocessor provides inclusion of header files , macro expansions, conditional compilation , and line control.
The C headers <stdnoreturn.h> and <threads.h> do not have C++ equivalents and their C headers are not supported in C++. C++ does not provide the C POSIX library as part of any standard, however it is legal to use in a C++ program. If used in C++, the POSIX headers are not prepended with a "c" at the beginning of the name, and all contain the .h ...
In the C and C++ programming languages, unistd.h is the name of the header file that provides access to the POSIX operating system API. [1] It is defined by the POSIX.1 standard, the base of the Single Unix Specification, and should therefore be available in any POSIX-compliant operating system and compiler.