terminate called after throwing an instance of 'std::out_of_range' what(): basic_string::substr

运行时报错：

terminate called after throwing an instance of 'std::out_of_range'
what():  basic_string::substr：__pos

Aborted (core dumped)

内存读取越界。

解释1：for example:
const std::string sTest( "test" );
sTest.substr( 0, 10 );
will raise the same exception, since you ask 10 characters, but only 5 ( sTest.length()) ) are available.

调试过，正常运行，无报错。

解释2：

Chances are you did something like:

std::string s("foo");

s.substr(5,1); //the length of the string is 3, 5 is out of bounds

调试过，确实会报错，out_of_range

解决方案：查找substr方法前后代码，排除可能的越界条件。