folly::gen::detail::Min< Selector, Comparer > Class Template Reference

#include <Base-inl.h>

Inheritance diagram for folly::gen::detail::Min< Selector, Comparer >:

Public Member Functions
	Min ()=default
	Min (Selector selector)
	Min (Selector selector, Comparer comparer)
template<class Value , class Source , class StorageType = typename std::decay<Value>::type, class Key = typename std::decay<invoke_result_t<Selector, Value>>::type>
Optional< StorageType >	compose (const GenImpl< Value, Source > &source) const
Public Member Functions inherited from folly::gen::Operator< Min< Selector, Comparer > >
ResultGen	compose (const GenImpl< Value, Source > &source) const
Public Member Functions inherited from folly::gen::FBounded< Self >
const Self &	self () const
Self &	self ()

Private Member Functions
template<typename T >
const T &	asConst (const T &t) const

Private Attributes
Selector	selector_
Comparer	comparer_

Additional Inherited Members
Protected Member Functions inherited from folly::gen::Operator< Min< Selector, Comparer > >
	Operator ()=default
	Operator (Operator &&) noexcept=default
	Operator (const Operator &)=default
Operator &	operator= (Operator &&) noexcept=default
Operator &	operator= (const Operator &)=default

Detailed Description

template<class Selector, class Comparer>
class folly::gen::detail::Min< Selector, Comparer >

Min - For a value which minimizes a key, where the key is determined by a given selector, and compared by given comparer.

This type is usually used through the singletone 'min' or through the helper functions 'minBy' and 'maxBy'.

auto oldest = from(people) | minBy([](Person& p) { return p.dateOfBirth; });

Definition at line 2213 of file Base-inl.h.

Constructor & Destructor Documentation

template<class Selector , class Comparer >

folly::gen::detail::Min< Selector, Comparer >::Min ( )

default

template<class Selector , class Comparer >

folly::gen::detail::Min< Selector, Comparer >::Min ( Selector  selector )

inlineexplicit

Definition at line 2225 of file Base-inl.h.

: selector_(std::move(selector)) {}

template<class Selector , class Comparer >

folly::gen::detail::Min< Selector, Comparer >::Min ( Selector  selector, Comparer  comparer  )

inline

Definition at line 2227 of file Base-inl.h.

References testing::Key(), type, and testing::Value().

      : selector_(std::move(selector)), comparer_(std::move(comparer)) {}

Member Function Documentation

template<class Selector , class Comparer >

template<typename T >

const T& folly::gen::detail::Min< Selector, Comparer >::asConst ( const T &  t ) const

inlineprivate

Definition at line 2218 of file Base-inl.h.

References folly::pushmi::detail::t.

                                     {
    return t;
  }

template<class Selector , class Comparer >

template<class Value , class Source , class StorageType = typename std::decay<Value>::type, class Key = typename std::decay<invoke_result_t<Selector, Value>>::type>

Optional<StorageType> folly::gen::detail::Min< Selector, Comparer >::compose ( const GenImpl< Value, Source > &  source ) const

inline

Definition at line 2235 of file Base-inl.h.

References folly::Optional< Value >::get_pointer(), min, folly::gen::move, v, and testing::Value().

                                                                            {
    static_assert(
        !Source::infinite,
        "Calling min or max on an infinite source will cause "
        "an infinite loop.");
    Optional<StorageType> min;
    Optional<Key> minKey;
    source | [&](Value v) {
      Key key = selector_(asConst(v)); // so that selector_ cannot mutate v
      if (auto lastKey = minKey.get_pointer()) {
        if (!comparer_(key, *lastKey)) {
          return;
        }
      }
      minKey = std::move(key);
      min = std::forward<Value>(v);
    };
    return min;
  }

Member Data Documentation

template<class Selector , class Comparer >

Comparer folly::gen::detail::Min< Selector, Comparer >::comparer_

private

Definition at line 2215 of file Base-inl.h.

template<class Selector , class Comparer >

Selector folly::gen::detail::Min< Selector, Comparer >::selector_

private

Definition at line 2214 of file Base-inl.h.

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The documentation for this class was generated from the following file:

• proxygen/folly/folly/gen/Base-inl.h