c++ - Warning: truncation from int to char, when using string::find_first_not_of

Question

We try to clean up our project and remove all warnings. I get warning for this line:

if(line.find_first_not_of('\n\t ') != string::npos) {

warning C4305: 'argument' : truncation from 'int' to 'char'

I am not sure what to do... Both values are size_t, not sure why it complains.

Answer 1

该警告具有误导性。它应该警告多字符到字符的转换，因为您使用'\n\t'的是（多字符）而不是"\n\t"（字符串）。

无论如何，您需要在这里使用双引号：

 if(line.find_first_not_of("\n\t ") != string::npos)

希望有帮助。