I had the same problem in my code. I was concatenating a string to create a string. Below is the part of code.
int scannerId = 1;
std:strring testValue;
strInXml = std::string(std::string("" \
"" + scannerId) + std::string("" \
"" \
"" + testValue) + "" \
"FALSE" \
"FALSE" \
""\
"");