jh::concepts::range_storage_traits< R, UseRefWrapper > Struct Template Reference

Trait defining how a range (or equivalent) is held inside a view or wrapper. More...

#include <jh/conceptual/range_traits.h>

Public Types
using	stored_t
	Type used internally to hold the source, based on reference category and policy.

Static Public Member Functions
static constexpr auto	wrap (R &&v) noexcept(std::is_nothrow_constructible_v< stored_t, R && >)
	Wraps a range/view/sequence according to the defined storage policy.
static constexpr decltype(auto)	get (stored_t &v) noexcept
	Retrieves a reference to the underlying source.
static constexpr decltype(auto)	get (const stored_t &v) noexcept
	Retrieves a reference to the underlying source.

Static Public Attributes
static constexpr bool	is_lvalue = std::is_lvalue_reference_v<R>
	Indicates whether the source is an lvalue reference.

Detailed Description

template<typename R, bool UseRefWrapper = false>
struct jh::concepts::range_storage_traits< R, UseRefWrapper >

Trait defining how a range (or equivalent) is held inside a view or wrapper.

range_storage_traits<R> defines the storage model for wrapper-based view types that internally hold another range, view, or sequence — for example: jh::ranges::range_adaptor and jh::ranges::vis_transform_view.

Policy Overview

• Rvalues / temporaries — stored by value.
• Lvalues — stored as references, optionally wrapped in std::reference_wrapper for safety.
• UseRefWrapper = true — enforces safe reference semantics, ensuring non-dangling access in deferred pipelines.
• UseRefWrapper = false — uses direct references for lightweight, local usage.

This trait allows range-holding views to remain agnostic to the lifetime and category of their sources, achieving consistent forwarding semantics across the entire jh::ranges ecosystem.

Template Parameters

R	Source range type to be stored.
UseRefWrapper	Whether lvalues should be stored as std::reference_wrapper.

Member Typedef Documentation

stored_t

template<typename R, bool UseRefWrapper = false>

using jh::concepts::range_storage_traits< R, UseRefWrapper >::stored_t

Initial value:

std::conditional_t<
               is_lvalue,
               std::conditional_t<UseRefWrapper,
                       std::reference_wrapper<std::remove_reference_t<R>>,
                       R>,
               std::remove_cvref_t<R>
       >

Type used internally to hold the source, based on reference category and policy.

Member Function Documentation

get() [1/2]

template<typename R, bool UseRefWrapper = false>

constexpr decltype(auto) jh::concepts::range_storage_traits< R, UseRefWrapper >::get ( const stored_t & v )

inlinestaticconstexprnoexcept

Retrieves a reference to the underlying source.

Parameters

v	Stored instance.

Returns

Constant / Mutable reference to the source.

get() [2/2]

template<typename R, bool UseRefWrapper = false>

constexpr decltype(auto) jh::concepts::range_storage_traits< R, UseRefWrapper >::get ( stored_t & v )

inlinestaticconstexprnoexcept

Retrieves a reference to the underlying source.

Parameters

v	Stored instance.

Returns

Constant / Mutable reference to the source.

wrap()

template<typename R, bool UseRefWrapper = false>

constexpr auto jh::concepts::range_storage_traits< R, UseRefWrapper >::wrap ( R && v )

inlinestaticconstexprnoexcept

Wraps a range/view/sequence according to the defined storage policy.

Parameters

v	The source range to wrap.

Returns

Stored representation (value or reference) suitable for internal retention.

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

• include/jh/conceptual/range_traits.h