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' compatibl
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 ...
in C? C has a keyword extern. For example:#include <stdio.h> int main() { extern int x; printf("x = %d\n", x); }Note the extern on the x. What does this do? Let’s compile it to find out:$ clang main.c Undefined symbols for architecture x86_64: "_x", referenced from...
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...
Example 02: Let’s open the same file again to update it a little. This time, we will be using the “main” method in our code. We have declared the variable “z” outside of the main method. The compilation of the file “test.c” throws an exception that the variable “z” has...
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....
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
1 constexpr说明符只能应用于变量或变量模板的定义、函数或函数模板的声明或文字类型的静态数据成员的声明...
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: ...