Second scope after struct definition

Question

I looked a bit into Eric Nieblers range library https://github.com/ericniebler/range-v3/ and there (/include/range/v3/utility/concepts.hpp, line 36) I found code of the form

constexpr struct valid_expr_t
{
    template<typename ...T>
    true_ operator()(T &&...) const;
} valid_expr {};

I am confused to the second scope/braces after valid_expr. What is the meaning of the whole construct. Is this even a struct definition? The syntax seems not allowed in C++98. What can go into these second pair of braces?

Some programmer dude · Accepted Answer · 2013-11-26 09:10:11Z

4

It's the C++11 uniform initialization syntax, and it simply initializes the valid_expr object.

It's like doing

struct valid_expr_t
{
    template<typename ...T>
    true_ operator()(T &&...) const;
};

constexpr valid_expr_t valid_expr {};

answered Nov 26, 2013 at 9:10

Some programmer dude

411k36 gold badges420 silver badges655 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Second scope after struct definition

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related