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++98

Compiler(s):

G++ 4.9.2

Libraries used:

STL: GNU ISO C++ Library, version 4.9.2

Qt project file: ./CppStdEqualExample1/CppStdEqualExample1.pro


include(../../ConsoleApplication.pri) #Or use the code below

# QT += core

# QT += gui

# greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

# CONFIG   += console

# CONFIG   -= app_bundle

# TEMPLATE = app

# CONFIG(release, debug|release) {

#   DEFINES += NDEBUG NTRACE_BILDERBIKKEL

# }

# QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++

# unix {

#   QMAKE_CXXFLAGS += -Werror

# }



include(../../Libraries/Boost.pri) #Or use the code below

# win32 {

#   INCLUDEPATH += \

#     ../../Libraries/boost_1_54_0

# }



SOURCES += main.cpp

./CppStdEqualExample1/main.cpp


#include <algorithm>

#include <cassert>

#include <vector>



#include <set>

int main()

{

  //Compare two identical std::vectors: prefer operator==

  {

    const std::vector<int> v { 0,1,2 };

    const std::vector<int> w { 0,1,2 };



    //Preferred syntax

    assert(v == w);

    //Less preferred, no unexpected behaviour

    assert(std::equal(v.begin(),v.end(),w.begin()));

  }

  //Compare two different std::vectors: prefer operator==

  {

    const std::vector<int> v { 0,1,2   };

    const std::vector<int> w { 0,1,2,3 };



    //Preferred syntax

    assert(v != w);

    //Less preferred, unexpected behaviour:

    //Only tests 3 (the size of v) elements

    //v and w do match for these

    assert(std::equal(v.begin(),v.end(),w.begin()));

    //Might result in access violations (as it might read v[3])?

    //assert(!std::equal(w.begin(),w.end(),v.begin()));

  }

  //Compare two container types: use std::equal

  {

    const std::vector<int> v { 0,1,2 };

    //Sorted container, will result in {0,1,2}

    const std::set<int> w { 2,1,0 };

    //This syntax does not work here anymore

    //assert(v == w);

    //Preferred syntax in this situation

    assert(std::equal(v.begin(),v.end(),w.begin()));

  }

}

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(C++) StdEqualExample1

Technical facts

Qt project file: ./CppStdEqualExample1/CppStdEqualExample1.pro

./CppStdEqualExample1/main.cpp