SetWindowTextW() helper function in c++ - c++

Question

I wonder whether there is a "better way" to supply SetWindowText "text" argument than this code:
wchar_t buffer[20];
Measures10nm.CIE_L = 100.3456f;
Measures10nm.CIE_a = -9.34f;
Measures10nm.CIE_b = -56.56f;
swprintf_s(buffer, 20, L"%.2f", Measures10nm.CIE_L);
SetWindowTextW(hEditCIE_L, buffer);
swprintf_s(buffer, 20, L"%.2f", Measures10nm.CIE_a);
SetWindowTextW(hEditCIE_a, buffer);
swprintf_s(buffer, 20, L"%.2f", Measures10nm.CIE_b);
SetWindowTextW(hEditCIE_b, buffer);
I tried to experiment with a function that I could supply a float to and who would return a wchar_t, since that's the type of argument SetTextWindow() requires but I have not been "successful" at it. I'm not even sure this is possible, technically, after all the time I experimented with various coding? Ideally, what I'd like to use is a function like this :
SetTextWindow(hEdit, floatToWchar_t(Measures10nm.CIE_L));
But I have not been able to code such a function?
I experimented with something along these lines :
wchar_t floatToWchar_t(float x)
{
wchar_t buffer[20];
swprintf_s(buffer, 20, L"%f", x);
return buffer;
}
But that does not work because wchar_t is an array, I suppose. I thought about using a pointer to the array but I can't conceptualize clearly how to do it.
Any help is appreciated. Please excuse the newbie question...

Answer 1

We're talking C++ here so forget about character arrays and use std::wstring and C++ streams.
#include <sstream>
std::wstringstream ss; // String-based stream.
float f = 3.14; // Our float.
ss << f; // Output the float to the stream.
SetWindowTextW(hWnd, ss.str().c_str()); // Covert to a `wchar_t` zero-terminated string.
You can easily wrap this in a function.
void SetWindowFloat(HWND hWnd, float f);
If you need to modify how the float is converted to a string, take a look at iomanip.

Answer 2

Modify for wstring ....
std::wstring floatToWideString(float x)
{
wchar_t buffer[20];
swprintf_s(buffer, 20, L"%f", x);
return buffer;
}
Then
void SetWindowText(HWND hwnd, const std::wstring& s)
{
SetWindowText(hwnd, s.c_str());
}
SetWindowText(hwnd, floatToWideString(3.1415f));
... but with all your calls to SetWindowText to the same hwnd, you're going to overwrite what's there....it's not like it is a line buffer.
Update:
Also, if you get so inclined to use use MFC, or just to use <atlstr.h>, there is a CString class that has a (LPCTSTR) cast operator.
Something like:
CStringW floatToWideCString(float x)
{
CStringW s;
s.Format(_T("%f"), x);
return s;
}
SetWindowText(hwnd, floatToWideCString(3.14));