optional_ref_tpl.h

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 *   Copyright (c) 2005-2026 by                                             *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
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 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
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#pragma once
 
#include <agrum/base/core/inline.h>
 
#include <agrum/base/core/optional_ref.h>
 
namespace gum {
 
 
  template < typename T >
  optional_ref< T >::optional_ref(std::nullopt_t) noexcept {}
 
  template < typename T >
  optional_ref< T >::optional_ref(T& ref) noexcept : _ptr_(&ref) {}
 
  template < typename T >
  optional_ref< T >::operator bool() const noexcept {
    return _ptr_ != nullptr;
  }
 
  template < typename T >
  bool optional_ref< T >::has_value() const noexcept {
    return _ptr_ != nullptr;
  }
 
  template < typename T >
  T& optional_ref< T >::value() const {
    if (!_ptr_) throw std::bad_optional_access();
    return *_ptr_;
  }
 
  template < typename T >
  T& optional_ref< T >::operator*() const {
    return value();
  }
 
  template < typename T >
  T* optional_ref< T >::operator->() const noexcept {
    return _ptr_;
  }
 
}   // namespace gum