CppNamespaceExample1.md

 

 

 

 

 

(C++) NamespaceExample1

 

 

namespace example 1: scopes is a namespace example.

In the example, three versions of the function SayHello reside in different namespaces: loud, soft and the global namespace.

 

• Download the Qt Creator project 'CppNamespaceExample1' (zip)

Technical facts

 

Operating system(s) or programming environment(s)

• Lubuntu 15.04 (vivid)

IDE(s):

• Qt Creator 3.1.1

Project type:

• Console application

C++ standard:

• C++11

Compiler(s):

• G++ 4.9.2

Libraries used:

• STL: GNU ISO C++ Library, version 4.9.2

 

 

 

 

 

Qt project file: ./CppNamespaceExample1/CppNamespaceExample1.pro

 

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TEMPLATE = app CONFIG += console CONFIG -= app_bundle CONFIG -= qt SOURCES += main.cpp QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++ unix {   QMAKE_CXXFLAGS += -Werror }

 

 

 

 

 

./CppNamespaceExample1/main.cpp

 

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#include <iostream> namespace loud {   void SayHello() { std::cout << "HELLO WORLD!\n"; } } //SayHello in the global namespace, ::SayHello() void SayHello() { std::cout << "Hello world\n"; } namespace soft {   void SayHello() { std::cout << "H.e.l.l.o w.o.r.l.d...\n"; } } int main() {   loud::SayHello();     //Call loud::SayHello   ::SayHello();         //Explicity call SayHello from global namespace   SayHello();           //Call the SayHello used, which is ::SayHello by default   using soft::SayHello; //Start using soft::SayHello   SayHello();           //Call the SayHello used, which is soft::SayHello now   soft::SayHello();     //Call soft::SayHello } /* Screen output: HELLO WORLD! Hello world Hello world H.e.l.l.o w.o.r.l.d... H.e.l.l.o w.o.r.l.d... Press <RETURN> to close this window... */