Question

A there any g++ options which can detect improper initialization of std::string with NULL const char*?

I was in the process of turning some int fields into std::string ones, i.e:

struct Foo
{
   int id;
   Foo() : id(0) {} 
};

…turned into:

struct Foo
{
   std::string id;
   Foo() : id(0) {} //oooops!
};

I completely overlooked bad ‘id’ initialization with 0 and g++ gave me no warnings at all. This error was detected in the run time(std::string constructor threw an exception) but I’d really like to detect such stuff in the compile time. Is there any way?

Answer 1

I think it is actually undefined behavior and not checked by the compiler. You are lucky that this implementation throws an exception.

However, you can avoid such problems by specifying that you want default or zero-initialization in a type-agnostic way:

struct Foo
{
   X id;
   Foo() : id() {} //note empty parenthesis
};