2019-06-21 22:11:42 +02:00
|
|
|
// Copyright 2019 The Abseil Authors.
|
|
|
|
|
//
|
|
|
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
|
|
|
// you may not use this file except in compliance with the License.
|
|
|
|
|
// You may obtain a copy of the License at
|
|
|
|
|
//
|
|
|
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
|
//
|
|
|
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
|
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
|
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
|
|
|
// See the License for the specific language governing permissions and
|
|
|
|
|
// limitations under the License.
|
|
|
|
|
|
|
|
|
|
#ifndef ABSL_RANDOM_INTERNAL_DISTRIBUTIONS_H_
|
|
|
|
|
#define ABSL_RANDOM_INTERNAL_DISTRIBUTIONS_H_
|
|
|
|
|
|
|
|
|
|
#include <type_traits>
|
|
|
|
|
|
|
|
|
|
#include "absl/meta/type_traits.h"
|
|
|
|
|
#include "absl/random/internal/distribution_caller.h"
|
|
|
|
|
#include "absl/random/internal/traits.h"
|
|
|
|
|
#include "absl/random/internal/uniform_helper.h"
|
|
|
|
|
|
|
|
|
|
namespace absl {
|
2019-12-12 19:36:03 +01:00
|
|
|
ABSL_NAMESPACE_BEGIN
|
2019-06-21 22:11:42 +02:00
|
|
|
namespace random_internal {
|
|
|
|
|
|
|
|
|
|
// In the absence of an explicitly provided return-type, the template
|
|
|
|
|
// "uniform_inferred_return_t<A, B>" is used to derive a suitable type, based on
|
|
|
|
|
// the data-types of the endpoint-arguments {A lo, B hi}.
|
|
|
|
|
//
|
|
|
|
|
// Given endpoints {A lo, B hi}, one of {A, B} will be chosen as the
|
|
|
|
|
// return-type, if one type can be implicitly converted into the other, in a
|
|
|
|
|
// lossless way. The template "is_widening_convertible" implements the
|
|
|
|
|
// compile-time logic for deciding if such a conversion is possible.
|
|
|
|
|
//
|
|
|
|
|
// If no such conversion between {A, B} exists, then the overload for
|
|
|
|
|
// absl::Uniform() will be discarded, and the call will be ill-formed.
|
|
|
|
|
// Return-type for absl::Uniform() when the return-type is inferred.
|
|
|
|
|
template <typename A, typename B>
|
|
|
|
|
using uniform_inferred_return_t =
|
|
|
|
|
absl::enable_if_t<absl::disjunction<is_widening_convertible<A, B>,
|
|
|
|
|
is_widening_convertible<B, A>>::value,
|
|
|
|
|
typename std::conditional<
|
|
|
|
|
is_widening_convertible<A, B>::value, B, A>::type>;
|
|
|
|
|
|
|
|
|
|
} // namespace random_internal
|
2019-12-12 19:36:03 +01:00
|
|
|
ABSL_NAMESPACE_END
|
2019-06-21 22:11:42 +02:00
|
|
|
} // namespace absl
|
|
|
|
|
|
|
|
|
|
#endif // ABSL_RANDOM_INTERNAL_DISTRIBUTIONS_H_
|
