Idiomatic C++ Atlas

The subjects of idiomatic C++ — from parameter passing to tooling-encoded style — each traced standard by standard. 35 topics across 8 categories, with examples from C++11 through the C++29 horizon.

C++11C++14C++17C++20C++23C++26C++29

Core semantics

6
Parameter passingIn/out/in-out conventions, sinks, views, forwarding references.Ownership & lifetimesRAII, smart pointers, observer conventions, rule of zero.Value vs. reference semanticsRegular types, when to copy, when identity matters.Move semanticsstd::move discipline, elision, relocation.InitializationBraces vs. parens, NSDMI, designated initializers, EB.Const & constexpr correctnessLogical constness and the growing compile-time subset.

Design

4
Class design=default/=delete, explicit, hidden friends, defaulted <=>.Error handlingExceptions, expected/optional, noexcept, contracts.Polymorphism choicevirtual vs variant+visit vs type erasure vs CRTP.API boundaries & vocabulary typesspan, optional, expected, enum class, strong types.

Generic & compile-time

3
Customization pointsADL two-step, CPOs, tag_invoke, the member pivot.Constraint styleFrom SFINAE to concepts and if constexpr.Named idiomsPimpl, copy-and-swap, erase-remove, overloaded, scope guards.

Code-level

4
Algorithms & ranges over raw loopsFrom <algorithm>+lambdas to composable lazy views.Casting disciplineNamed casts, bit_cast, narrowing, punning.Concurrency idiomsLocks, atomics, cancellation, lock-free reclamation.Physical designHeaders, ODR, inline variables, modules.

Compile-time & language mechanics

6
Coroutine machineryPromise types, awaitables, symmetric transfer, generators.Async compositionFrom futures to senders/receivers and structured concurrency.UB & object lifetimelaunder, implicit lifetimes, start_lifetime_as, erroneous behavior.Declaration styleauto policy, CTAD, structured bindings, placeholders.Lambda idiomsIIFE, init-capture, stateless lambdas, recursion.Name lookup hygieneADL control, namespaces, using enum.

Memory & performance

4
Allocator awarenessallocator_traits, PMR, arenas, allocate_at_least.Performance idiomsreserve, noexcept moves, layout, hints, SIMD.Code-size controlextern template, erased cores, instantiation discipline.Global state & init orderMagic statics, inline variables, constinit.

Text, numbers, time

4
String handlingstring_view rules, to_chars, format/print, encodings.Integer hygieneFixed widths, safe compares, saturating arithmetic.chrono disciplineTyped durations, clocks, calendars, zones.Comparators & hashingTransparent lookup, <=> rollout, hash composition.

Boundaries & practice

4
C interop & ABIextern C facades, opaque handles, out_ptr, #embed.Freestanding & embedded subsetNo-heap, no-exception C++ on constrained targets.Feature detection & migrationFeature-test macros, shims, standard-by-standard adoption.Tooling-encoded idiomWarnings, clang-tidy, hardened libraries — style as code.

C++26 entries follow the final working draft (N5032, Dec 2025) — compiler support is still early. C++29 rows are direction only: proposals under discussion, nothing adopted. Hollow dots on a card mark those direction-only rows.