folly::gen::detail::Count Class Reference

#include <Base-inl.h>

Inheritance diagram for folly::gen::detail::Count:

Public Member Functions
	Count ()=default
template<class Source , class Value >
size_t	compose (const GenImpl< Value, Source > &source) const
Public Member Functions inherited from folly::gen::Operator< Count >
ResultGen	compose (const GenImpl< Value, Source > &source) const
Public Member Functions inherited from folly::gen::FBounded< Self >
const Self &	self () const
Self &	self ()

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

Detailed Description

Count - for simply counting the items in a collection.

This type is usually used through its singleton, 'count':

auto shortPrimes = seq(1, 100) | filter(isPrime) | count;

Definition at line 2131 of file Base-inl.h.

Constructor & Destructor Documentation

folly::gen::detail::Count::Count ( )

default

Member Function Documentation

template<class Source , class Value >

size_t folly::gen::detail::Count::compose ( const GenImpl< Value, Source > &  source ) const

inline

Definition at line 2136 of file Base-inl.h.

References folly::gen::foldl(), and testing::Value().

                                                             {
    static_assert(!Source::infinite, "Cannot count infinite source");
    return foldl(
               size_t(0), [](size_t accum, Value /* v */) { return accum + 1; })
        .compose(source);
  }

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

• proxygen/folly/folly/gen/Base-inl.h