CODEWITHSUNDEEP
c++c++03c++builder-xe5
M.M
M.M

Reputation: 141648

Braced initialization in C++03

Is this program supposed to correctly initialize the string, in C++03?

#include <iostream>
#include <string>

struct A
{
    std::string s;
};

int main()
{
    A a = { };
    std::cout << a.s.size() << std::endl;

}

Using bcc32 6.70, the output is 256 , and inspecting the string in the debugger, its internal pointers appear to be garbage addresses.

Upvotes: 1

Views: 343

Answers (1)

Praetorian
Praetorian

Reputation: 109249

A is an aggregate and C++03 allows initialization of aggregates using a braced initializer-list. If the initializer-list is empty, then each member of the aggregate is value initialized.

From C++03 [dcl.init.aggr]/8

... An empty initializer-list can be used to initialize any aggregate. If the aggregate is not an empty class, then each member of the aggregate shall be initialized with a value of the form T() (5.2.3), where T represents the type of the uninitialized member.

In your example the std::string member should be default initialized.

Upvotes: 5

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