Created on 2023-01-06.00:00:00 last changed 3 weeks ago
Proposed resolution:
This wording is relative to N4917.
Modify [ranges.syn] as indicated:
#include <compare> // see [compare.syn] #include <initializer_list> // see [initializer.list.syn] #include <iterator> // see [iterator.synopsis] namespace std::ranges { […] // [range.utility.conv], range conversions template<class C, input_range R, class... Args> requires (!view<remove_cv_t<C>>) constexpr C to(R&& r, Args&&... args); // freestanding template<template<class...> class C, input_range R, class... Args> constexpr auto to(R&& r, Args&&... args); // freestanding template<class C, class... Args> requires (!view<remove_cv_t<C>>) constexpr auto to(Args&&... args); // freestanding template<template<class...> class C, class... Args> constexpr auto to(Args&&... args); // freestanding […] }
Modify [range.utility.conv.to] as indicated:
template<class C, input_range R, class... Args> requires (!view<remove_cv_t<C>>) constexpr C to(R&& r, Args&&... args);-1- Returns: An object of type C constructed from the elements of r in the following manner:
[…]
Modify [range.utility.conv.adaptors] as indicated:
template<class C, class... Args> requires (!view<remove_cv_t<C>>) constexpr auto to(Args&&... args); template<template<class...> class C, class... Args> constexpr auto to(Args&&... args);-1- Returns: A range adaptor closure object ([range.adaptor.object]) f that is a perfect forwarding call wrapper ([func.require]) with the following properties:
[…]
The intention of ranges::to is to construct a non-view object, which is reflected in its constraint that object type C should not model a view.
The specification allows C to be a const-qualified type which does not satisfy view such as const string_view, making ranges::to return a dangling view. We should ban such cases.
History | |||
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Date | User | Action | Args |
2023-01-06 16:23:59 | admin | set | messages: + msg13181 |
2023-01-06 00:00:00 | admin | create |