C++ unknown errors

Question

I have the following function in C++:

std::wstring decToDeg(double input)
{
    int deg, min;
    double sec, sec_all, min_all;
    std::wstring output;

    sec_all = input * 3600;
    sec = Math::Round(static_cast<int>(sec_all) % 60, 3); //code from @spin_eight answer
    min_all = (sec_all - sec) / 60;
    min = static_cast<int>(min_all) % 60;
    deg = static_cast<int>(min_all - min) / 60;
    output = deg + L"º " + min + L"' " + sec + L"\"";

    return output;
}

When I try to compile I get this error:

error C2679: binary '=' : no operator found which takes a right-hand operand of type 'System::String ^' (or there is no acceptable conversion)

What can I do to correct these two errors in my function?

EDIT: solved

std::wstring decToDeg(double input)
{
    int deg, min;
    double sec, sec_all, min_all;

    sec_all = input * 3600;
    sec = Math::Round(static_cast<int>(sec_all) % 60, 3);
    min_all = (sec_all - sec) / 60;
    min = static_cast<int>(min_all) % 60;
    deg = static_cast<int>(min_all - min) / 60;

    std::wostringstream output;
    output << deg << L"º " << min << L"' " << sec << L"\"";

    return output.str();
}

Also, you're trying to sum numbers with strings, which can't be done like this in C++ — Kiril Kirov, Nov 22 '12 at 07:37
Could you tell me what to do to solve these errors? I am totally new to C++... — Victor, Nov 22 '12 at 07:40
Look at http://stackoverflow.com/questions/64782/how-do-you-append-an-int-to-a-string-in-c for various ways to fix #2 — Karthik T, Nov 22 '12 at 07:46
Please don't write solutions in questions. Write solutions in _answers_. — Lightness Races in Orbit, Nov 23 '12 at 14:14

score 1 · Answer 1 · answered Nov 22 '12 at 07:42

1

sec = Math::Round(static_cast<int>(sec_all) % 60, 3);

answered Nov 22 '12 at 07:42

spin_eight

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output = std::to_string(deg) + L"º " +std::to_string(min) + L"' " + std::to_string(sec) + L"\""; – spin_eight Nov 22 '12 at 07:48

score 1 · Answer 2 · answered Nov 22 '12 at 07:44

1

You cannot use modulo on doubles. Modulo on doubles:

 int result = static_cast<int>( a / b );
 return a - static_cast<double>( result ) * b;

answered Nov 22 '12 at 07:44

ISTB

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score 1 · Accepted Answer · answered Nov 22 '12 at 07:48

1

You could use a string stream to construct output, like this:

std::wostringstream output;
output << deg << L"º " << min << L"' " << sec << L"\"";

return output.str();

answered Nov 22 '12 at 07:48

Angew is no longer proud of SO

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@Victor What error? BTW, of course you have to remove your original declaration of `output` as a `wstring`, and you have to `#include `. – Angew is no longer proud of SO Nov 22 '12 at 08:08

score 0 · Answer 4 · answered Nov 22 '12 at 07:45

For the first error try this:

 min = (static_cast<int>(min_all) ) % 60;

This should make sure the cast will be completed first, before trying to do any other calculating.

If your other error is not an error that was caused by the first error, you may want to try using stringstream. It behaves like a normal I/O stream and is thus ideal for formatting strings.

C++ unknown errors

4 Answers4