////
Copyright 2020 Peter Dimov
Distributed under the Boost Software License, Version 1.0.
https://www.boost.org/LICENSE_1_0.txt
////

[#owner_less]
# owner_less
:toc:
:toc-title:
:idprefix: owner_less_

## Description

`owner_less<T>` is a helper function object that compares two smart
pointer objects using `owner_before`. It is only provided for compatibility
with {cpp}11 and corresponds to the standard component of the same name.

When using Boost smart pointers, the use of `owner_less` is unnecessary, as
the supplied `operator<` overloads (and, correspondingly, `std::less`) return
the same result.

## Synopsis

`owner_less` is defined in `<boost/smart_ptr/owner_less.hpp>`.

```
namespace boost {

  template<class T = void> struct owner_less
  {
    typedef bool result_type;
    typedef T first_argument_type;
    typedef T second_argument_type;

    template<class U, class V> bool operator()( U const & u, V const & v ) const noexcept;
  };
}
```

## Members

```
template<class U, class V> bool operator()( U const & u, V const & v ) const noexcept;
```
[none]
* {blank}
+
Returns::
  `u.owner_before( v )`.