For example: extern "C" { void foo(); } extern "C" makes a function-name in C++ have 'C' linkage (compiler does not mangle the name) so that client C code can link to (ie use) your function using a 'C' compatible header file that contains just the declaration of your function....
Example Code: intprintf(constchar*format,...);intmain(){printf("I'm learning the use of Extern in C++");} We use theexternkeyword in C++ programming to eliminate this issue. Whenever the C++ compiler finds the code inside theextern "C" {}block, it makes sure that the name of the ...
How to handle C symbols when linking from C++? In C, names may not be mangled as C doesn’t support function overloading. So how to make sure that name of a symbol is not changed when we link a C code in C++. For example, see the following C++ program that uses printf() functio...
Minimal runnable C from C++ example For the sake of completeness and for the newbs out there, see also:How to use C source files in a C++ project? Calling C from C++ is pretty easy: each C function only has one possible non-mangled symbol, so no extra work is required. main.cpp #...
3.4 实例代码 (Example Code) 4. extern关键字的使用场景 4.1 共享全局变量 4.2 链接C和C++库 4.3 模块化编程 5. extern关键字的底层原理 5.1 链接过程中的作用 5.2 编译器如何处理extern 6. extern关键字在多态中的运用 (The Use of the extern Keyword in Polymorphism) 6.1 用于实现动态链接 (Implementing ...
extern关键字还有一个重要的用途是用于链接C和C++代码。当我们在C++代码中使用extern "C"时,我们告诉编译器按照C语言的规则来链接代码。 例如,如果我们有一个C语言的库文件(比如clib.c),我们可以在C++代码中通过extern "C"来引用这个库。 // clib.cvoid c_func() {// function definition in C}// main....
actualdefinition,resultinginillegalaccessatruntime.The statementshouldbechangedtoexternchara[]. 2),exampleanalysisasfollows,ifa[]="ABCD",isanexternal variableofa=0*61626364(ABCDASCII,*acodevalue) apparentlyhasnomeaningclearlypointedtobytheaspace(0 ...
c call c++ example extern "C", 引用参考:http://hi.baidu.com/chong_jing/item/86a60aac0db2ec13a9cfb762http://www.cnblogs.com/skynet/archive/2010/07/10/1774964.htmlhttp://www.cnblogs.com/xulei/archive/2006/11/12/558139.html
Microsoft C++ supports the strings"C"and"C++"in thestring-literalfield. All of the standard include files use theextern "C"syntax to allow the run-time library functions to be used in C++ programs. Example The following example shows how to declare names that have C linkage: ...
Learn about the effect of extern 'C' in C++ and how it impacts function linkage and interoperability between C and C++ code.