c++ - std::stringstream.str() outputs garbage -

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i need save bunch of image files numbered indices. trying construct these filenames using stringstream. however, stringstream.str() not seem return filename, rather returns garbage.

here code:

std::stringstream filename; filename << filepath << fileindex << ".png"; bool ret = imwrite(filename.str(),frame, compression_params); fileindex++; printf("wrote %s\n", filename.str());

here output 1 execution:

wrote ╠±0 wrote ╠±0 wrote ╠±0 wrote ╠±0

here output execution:

wrote ░‗v wrote ░‗v wrote ░‗v wrote ░‗v

any suggestions? imwrite opencv function, , have [code]using namespace cv;[/code] @ top of file - there interference between opencv , std?

you can't pass non-pod type std::string c-style variadic function printf.

you use c++ output:

std::cout << "wrote " << filename.str() << '\n';

or, if old-school weirdness, extract c-style string c-style output:

printf("write %s\n", filename.str().c_str());

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