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C++ In a Nutshell
book

C++ In a Nutshell

by Ray Lischner
May 2003
Intermediate to advanced content levelIntermediate to advanced
808 pages
32h 24m
English
O'Reilly Media, Inc.
Content preview from C++ In a Nutshell

Name

extern storage class — External storage class specifier

Synopsis

               storage-class-specifier := extern
linkage-specification ::= extern string-literal { [declaration-seq] } | 
    extern string-literal 
               declaration
            

The extern storage class specifier marks a declaration as having external linkage. An external object or function can be defined in one file and used in other files.

image with no caption

The extern keyword can also be used to specify language linkage: you provide the language name as a string literal. The "C++" language is the default. "C" linkage is also supported. Other languages are implementation-defined.

Example

extern "C" int callable_from_C(int x, int y);
extern void func(int);
extern const double pi;

See Also

declaration, static, type, Chapter 2

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Publisher Resources

ISBN: 059600298XSupplemental ContentErrata Page