OutputDebugString method seems rather tedious and seems only limited to string and not polymorphic. What should I do if I want to output some integer or other variable type ?
Hope some function like std::cout exists !
- Does this answer your question? Simplest way to write output message to 'output window' in Visual Studio 2010?Josh Correia– Josh Correia2020-10-29 23:23:05 +00:00Commented Oct 29, 2020 at 23:23
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5 Answers
I'm pretty sure you could write a streambuf implementation that outputs via OutputDebugString. It's not entirely straight forward, but possible.
It would certainly be possible to use something like this:
std::stringstream ss; ss << something << another << variable << here << endl; OutputDebugString(ss.str().c_str()); You may need to use MultiByteToWideChar to convert the c_str() to a wide string, if you have "UNICODE" enabled in your project.
8 Comments
CDT
VS reported incomplete type error at
std::stringstream ss ?
Mats Petersson
You need to
#include <sstream> then.CDT
Also reported incompatible type error at OutputDebugString(ss.str().c_str()); ?
const char * not compatible with LPCWSTR.CDT
After a minute or two the incompatible type error disappears automatically.
Cody Gray
@CDT It still won't compile, though. Use
std::wstringstream instead (note the w), since all Windows code should be written using Unicode strings. |
Since the accepted answer doesn't really provide a working version:
If you're not concerned with unicode - though you probably should be if you're shipping anything, I'll assume you won't be shipping it with OutputDebugString included - you can use one of the other versions, such as OutputDebugStringA:
stringstream ss; ss << "Hello World\n"; OutputDebugStringA(ss.str().c_str()); 
Comments
Use a class like this:
class stringbuilder { public: stringbuilder() { } template< class T > stringbuilder& operator << ( const T& val ) { os << val; return *this; } operator std::string () const { return os.str(); } private: std::ostringstream os; }; And pass the output to a wrapper around OutputDebugString (or anything else that logs strings only):
void MyOutputDebugString( const std::string& s ) { ::OutputDebugString( s.c_str() ); } //usage: MyOutputDebugString( stringbuilder() << "integer " << 5 ); 
2 Comments
CDT
Thanks, but it seems I got some stackoverflow with this method.
stijn
that's probably beacuse the OutputDebugString warpper is in the global namespace, it shouldn't be there, edited. Anyway the principle in this answer is exactly the same as Mats Petersson's, just written in a reusable way.
A macro for Mats Petersson's answer, with unicode support:
#define odslog(msg) { std::wstringstream ss; ss << msg; OutputDebugStringW(ss.str().c_str()); } Usage:
odslog("A string " << 123123 << L"A wide string" << "\n"); 
Comments
In addition, if you use MFC then you can use TRACE TRACE1 TRACE2 ... macros that work like printf to the debug output.
