收藏 不显示删除回复显示所有回复显示星级回复显示得分回复 标准C++中，如何获取std::wstring定义的字符串的字节数[问题点数:80分]

    wstrData = L"6564我们的国家"; 
    setlocale(LC_ALL, "Chinese-simplified");
    int requiredSize = wcstombs( NULL, wstrData.c_str(), 0); 
    std::wcout << requiredSize <<std::endl; 

#include <iostream>
#include <string.h>
using namespace std;

int main()
{
    cout<<sizeof L"6564我们的国家";
    return 0;
}

#include <iostream>
#include <string>

using namespace std;

int main()
{
    wstring s1(L"6564我们的国家");
    
    cout << sizeof(L"6564我们的国家") << endl;
    cout << sizeof(s1) << endl;
    
    s1.reserve(28);
    cout << sizeof(L"6564我们的国家") << endl;
    
    s1.reserve(10);
    cout << sizeof(L"6564我们的国家") << endl;
    
    return 0;
}

#include <iostream>
#include <string>
#include <locale>

using namespace std;

int main()
{
    setlocale(LC_ALL, "");
    
    wstring s1(L"6564我们的国家");
    
    cout << sizeof(L"6564我们的国家") << endl;
    wcout << s1 << " : " << sizeof(s1) << endl;
    
    s1.reserve(28);
    wcout << s1 << " : " << sizeof(s1) << endl;
    
    s1.resize(1);
    wcout << s1 << " : " << sizeof(s1) << endl;
    
    return 0;
}

wcout << s1 << " : " << s1.length() * sizeof(wchar_t) << endl;

#include <iostream>
#include <string>
#include <locale>

using namespace std;

int main()
{
    setlocale(LC_ALL, "");
    
    wstring s1(L"6564我们的国家");
    wcout << s1 << " : " << s1.length() * sizeof(wchar_t) << endl;
    s1.resize(5);
    wcout << s1 << " : " << s1.length() * sizeof(wchar_t) << endl;
    return 0;
}

#include <iostream>
#include <string>

using namespace std;

class StringBase
{
protected:
    size_t _len;
};

class WString : public StringBase
{
public:
    wchar_t* _p;
    size_t _size;
};

int main(int argc, char **argv)
{
    string s1;
    wstring s2;
    WString s3;

    cout << sizeof(s1) << endl;
    cout << sizeof(s2) << endl;
    cout << sizeof(s3) << endl;
    return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{
    wstring ws;
    while(true) {
        getline(wcin, ws);
        if (!wcin || wcin.fail())
            break;
        wcout<<ws<<L" has  "<<ws.size()<<L" char(s) and need "
            <<ws.size() * sizeof(wstring::value_type) << L"bytes memory at least.\n";
    }
    return 0;
}

one
one has  3 char(s) and need 12bytes memory at least.
two
two has  3 char(s) and need 12bytes memory at least.
three
three has  5 char(s) and need 20bytes memory at least.
four
four has  4 char(s) and need 16bytes memory at least.
ten
ten has  3 char(s) and need 12bytes memory at least.
hundred
hundred has  7 char(s) and need 28bytes memory at least.
thousand
thousand has  8 char(s) and need 32bytes memory at least.

    wstring strTest(L"hello你好");
    size_t szBytes = strTest.size() * sizeof(std::wstring::value_type) ;