Question

I m目前概述了C++11的新特征,目前原因不明,其中一些没有汇编。根据海合会的联邦武装部队情况,我使用46.020100703(experimental)(GCC)版本,我所尝试的所有特征都是支持。我试图用 st升到C++0x和 st=gnu++0x旗进行汇编。

Non member begin() & end()

例如,我wan不使用非成员,开始()和结束(),其成文法如下:

#include <iostream>
#include <map>
#include <utility>
#include <iterator>

using namespace std;
int main ( ) {
    map < string, string > alias;
    alias.insert ( pair < string, string > ( "ll", "ls -al" ) );
    // ... Other inserts

    auto it = begin(alias);
    while ( it != end(alias) ) {
        //...
    }

而且,我知道,

nonMemberBeginEnd//main.cc:15:24: error: ‘begin’ was not declared in this scope
nonMemberBeginEnd//main.cc:15:24: error: unable to deduce ‘auto’ from ‘<expression error>’ // Ok, this one is normal.
nonMemberBeginEnd//main.cc:16:26: error: ‘end’ was not declared in this scope

我是否需要包括特别负责人?

For range

My second (and last) question is weirder because It cannot depend on black magic hidden header that I might had not included.

The following Code :

for ( auto kv : alias )
    cout << kv.first << " ~ " << kv.second << endl;

下面的错误:

rangeFor/main.cc:15:17: error: expected initializer before ‘:’ token

我希望,我的问题不会成为你们的gu,也不要 too,你们会帮助我发现什么错误。

Answer 1

It works on gcc 4.6.1:

#include <iostream>
#include <map>
#include <string>

int main(int argc, char** argv) {
    std::map<std::string, std::string> alias = {{"key", "value"}};
    for (auto kv: alias)
        std::cout << kv.first << " ~ " << kv.second << std::endl;

    auto it = begin(alias);
    while (it != end(alias) ) {
        std::cout << (*it).first << " ~ " << (*it).second << std::endl;
        it++;
    }
    return EXIT_SUCCESS;
}

结果:

# /opt/gcc-4.6.1/bin/g++-4.6 --std=c++0x test.cc -o test && ./test
key ~ value
key ~ value

Non member begin() & end()

For range

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