Croydon 2026

March 2026 plenary · adopted into C++26
48papers adopted
27features touched
← Kona 2025Brno 2026 →

std::execution (senders/receivers)

5 papers
P3373R4Of Operation States and Their LifetimesC++26P3826R5Fix Sender Algorithm CustomizationC++26P3986R1A Wording Strategy for Inlinable ReceiversC++26P4154R0Renaming various execution thingsC++26P4159R0Make sender_in and receiver_of exposition-onlyC++26

Reflection

4 papers
P3598R0CWG 3158 – const-ification of Splice ExpressionsC++26P3795R2Miscellaneous Reflection CleanupC++26P3856R8New reflection metafunction - is_structural_typeC++26P4156R0Rename meta::has_ellipsis_parameter to meta::is_vararg_functionC++26

std::simd

4 papers
P3690R1Consistency fix: Make simd reductions SIMD-genericC++26P3844R4Reword [simd.math] for consteval conversionsC++26P3932R0Fix LWG4470: Fix integer-from in [simd]C++26P4012R1Value-preserving consteval broadcast to simd::vecC++26

Core & Library issue resolutions

3 papers
P4145R0C++ Standard Library Ready Issues to be moved in Croydon, Mar. 2026C++26P4146R0C++ Standard Library Immediate Issues to be moved in Croydon, Mar. 2026C++26P4160R0Core Language Working Group "ready" Issues for the March, 2026 meetingC++26

Coroutine task type

3 papers
P3941R4Scheduler AffinityC++26P3980R1Task’s Allocator UseC++26P4151R1Rename affine_onC++26

Ranges (C++26)

3 papers
P3059R2Making user-defined constructors of view iterators/sentinels privateC++26P3725R3Filter View Extensions for Safer Use, Rev 3C++26P3828R1Rename the to_input view to as_inputC++26

constant_wrapper & nontype

2 papers
P3948R1constant_wrapper is the only tool needed for passing constant expressions via function argumentsC++26P3978R3constant_wrapper should unwrap on call and subscriptC++26

Library constexpr-ification (C++26)

2 papers
P3450R1Extend std::is_within_lifetimeC++26P3842R2A conservative fix for constexpr uncaught_exceptions() and current_exception()C++26

Object lifetime & unions

2 papers
P3726R2Adjustments to Union Lifetime RulesC++26P3769R1Clarification of placement new deallocationC++26

Parallel scheduler

2 papers
P3804R2Iterating on parallel_schedulerC++26P3927R2task_scheduler support for parallel bulk executionC++26

Templates & concepts (core)

2 papers
P4004R1Reconsider CWG 1395 "Partial ordering of variadic templates reconsidered"C++26P4149R1Define "immediate context"C++26

#embed & preprocessor (C++26/29)

1 paper
P4136R2#line is not in line with existing implementationC++26

Atomics & memory model

1 paper
P3936R1Safer atomic_ref::address (FR-030-310)C++26

Constant evaluation (C++26)

1 paper
P4143R0Constant evaluation when?C++26

Core wording overhauls

1 paper
P3924R1Fix inappropriate font choices for "declaration"C++26

CTAD improvements

1 paper
P3865R3Class template argument deduction (CTAD) for type template template parametersC++26

Exceptions & exception_ptr

1 paper
P3981R2Better return types in std::inplace_vector and std::exception_ptr_castC++26

Formatting improvements (C++26/29)

1 paper
P3953R3Rename std::runtime_formatC++26

inplace_vector

1 paper
P4022R0Remove try_append_range from inplace_vector for nowC++26

Iterators & algorithms (misc)

1 paper
P3787R2Adjoints to "Enabling list-initialization for algorithms": uninitialized_fillC++26

mdspan

1 paper
P3982R2Split strided_slice into extent_slice and range_slice for C++26C++26

NB-comment omnibus & housekeeping

1 paper
P3886R0Wording for AT1-057C++26

Random numbers

1 paper
P4037R1Supporting signed char and unsigned char in random number generationC++26

Saturation arithmetic

1 paper
P4052R0Renaming saturation arithmetic functionsC++26

std::span

1 paper
P4144R1Remove span’s initializer_list constructor for C++26C++26

type_order

1 paper
P4140R0Proposed resolution for US70-126: allow incomplete types in type_orderC++26

Type-erased callables

1 paper
P3961R1Less double indirection in function_refC++26