04 — Reference Sites (Daily-Lookup Layer)

Bookmark every URL in this file on Day 1. These are the sites you will hit dozens of times per week for the rest of your C++ career. All URLs verified live July 2026.

Tier S — open every day

cppreference.com

  • URL: https://en.cppreference.com/w/

  • What it is: The community-maintained reference for the C++ standard library and language. More accurate than the ISO standard itself for most practical questions because it merges the standard text with worked examples and version-by-version deltas.

  • Cost: Free. No account. Mirrored at https://cppreference.com and downloadable for offline use.

  • Offline archive: https://en.cppreference.com/w/Cppreference:Archives — download the HTML tarball, open locally. Useful when you code on planes / flaky internet (India domestic flights, Bangalore power cuts, etc.).

  • How to use: When you type std::something in your editor, hitting the docs shortcut should take you to en.cppreference.com/w/cpp/.../something. Every major C++ editor extension supports this.

  • Verdict: The single most important C++ URL. Bookmark, install offline copy, memorize the URL structure.

godbolt.org — Compiler Explorer

  • URL: https://godbolt.org

  • Author: Matt Godbolt (also gives excellent CppCon talks).

  • What it is: Paste C++, get assembly output from any compiler at any optimization level. Compare compilers side-by-side. Share a URL that snapshots the exact code + flags + compiler.

  • Cost: Free. Runs on the author’s infra (donation-supported); commercial version “Compiler Explorer Enterprise” exists for on-prem needs.

  • When to reach for it:

    • “Does this if constexpr actually elide the branch?”

    • “Is my std::variant visit as fast as a switch?”

    • “Which compiler warns about this?”

    • Sharing code in a GitHub issue / Stack Overflow / Discord — always use a godbolt link, never raw pasted code.

  • Verdict: Second-most-important C++ URL. Learning to read (a little) assembly is a career-defining skill; godbolt is how you learn without leaving the browser.

isocpp.org

  • URL: https://isocpp.org

  • What it is: The official home of Standard C++ on the web. News, standardization status, papers announcements, FAQ.

  • Highlights: Blog aggregator (/blog) surfaces every important C++ news item across the internet — subscribe via RSS. FAQ section is the C++ FAQ Lite descendant, curated by Marshall Cline.

  • Verdict: The community-official newsfeed. Bookmark and RSS.

open-std.org — WG21 papers

  • URL: https://www.open-std.org/jtc1/sc22/wg21/docs/papers/

  • What it is: The archive of every ISO C++ committee paper. Numbered by year: 2026/ contains all papers submitted in 2026.

  • How to use: Look up a paper number cited in a talk. Read only the abstract + motivation section unless you have real reason to go deeper.

  • Verdict: Reference-only. Not for browsing.

Tier A — open several times per week

quick-bench.com

  • URL: https://quick-bench.com

  • What it is: In-browser Google Benchmark runner. Paste two implementations, get a side-by-side benchmark chart. Same author as godbolt (matt godbolt).

  • Caveat: Runs on shared cloud infrastructure — results have noise. Good for order-of-magnitude comparisons; not for tuning to 5% differences.

  • Verdict: Best free tool for “is my new code faster than the old one?” prototyping.

cppinsights.io

  • URL: https://cppinsights.io

  • Author: Andreas Fertig.

  • What it is: Rewrites your source code to show what the compiler actually generates — template instantiations expanded, lambdas rewritten as classes, range-for rewritten as iterator loops, structured bindings expanded, coroutines de-syntactic-sugared.

  • When to reach for it:

    • “What does this lambda capture actually copy?”

    • “What’s this template deducing to?”

    • “How does structured binding actually assign?”

    • “What does my coroutine actually look like?”

  • Verdict: The teaching companion to godbolt — godbolt shows machine truth, cppinsights shows source truth.

clang.llvm.org (Clang / LLVM docs)

  • URL: https://clang.llvm.org and https://llvm.org/docs/

  • What: Clang command-line reference, diagnostic flags, sanitizer docs (ASan/UBSan/TSan/MSan), Clang static analyzer, clang-tidy check catalog (https://clang.llvm.org/extra/clang-tidy/checks/list.html), clang-format options.

  • Verdict: You will look up clang-tidy check names constantly. Bookmark the checks catalog directly.

gcc.gnu.org

  • URL: https://gcc.gnu.org — GCC command-line docs.

  • Highlights: GCC extensions doc (https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Extensions.html) matters when reading Linux-adjacent C++ code that uses __attribute__ or __builtin_*.

  • Verdict: Bookmark. Reach when Clang and GCC disagree on your code (they will).

en.cppreference.com/w/cpp/compiler_support

  • URL: https://en.cppreference.com/w/cpp/compiler_support — the compiler-support matrix.

  • What it is: Which C++20/23/26 features work in which Clang/GCC/MSVC version. Non-obvious answers to “can I use std::print yet?”

  • Verdict: Consult before adopting a shiny new feature.

Tier B — reach for occasionally

awesome-cpp on GitHub

  • URL: https://github.com/fffaraz/awesome-cpp

  • What it is: Community-curated list of C++ libraries, tools, and resources. Categorized. Currently ~14k stars, still actively maintained (last commit within the last 30 days as of July 2026).

  • When to use: “I need a JSON library / logging library / HTTP client” — start here for a shortlist.

  • Companion: https://github.com/rigtorp/awesome-modern-cpp — more curated, modern-C++-only.

hackingcpp.com

  • Reference site with visual STL / algorithm cheat sheets. Covered in 02_online_courses.md.

pvs-studio.com/en/blog/ (deep bug archaeology)

  • URL: https://pvs-studio.com/en/blog/

  • What: PVS-Studio is a commercial C++ static analyzer; their blog runs “we found N bugs in $famous_open_source_project” posts that are unironically some of the best bug-pattern education you can find.

  • Verdict: Read a random one every few weeks; you’ll pattern-match bugs in your own code.

stackoverflow.com/tags/c%2B%2B

  • URL: https://stackoverflow.com/questions/tagged/c%2B%2B

  • How to use: Post-2015 answers only. Pre-C++11 answers on Stack Overflow are actively misleading for a modern learner. Filter by “newest” and by presence of the c++20 / c++23 sub-tag.

  • Community sentiment: SO’s C++ tag has a reputation for gruffness. Ask on r/cpp_questions or the #include<C++> Discord first (see 10_communities/). But reading SO answers, filtered to recent, is still valuable.

en.cppreference.com/w/cpp/language

  • Language reference (as opposed to library reference). Bookmark separately — you’ll go here often when learning templates, concepts, coroutines.

Tier C — nice to have

cppmap.md community roadmap

  • Not a specific URL; various “C++ roadmap” GitHub repos exist (search “cpp roadmap github”). All are less rigorous than your own roadmap in this repo. Skip unless curious.

p1144.godbolt.org and other feature-preview forks

  • Preview forks of Compiler Explorer that have specific WG21 papers pre-applied (e.g., relocatable types). Only when hunting specific feature previews.

www.bfilipek.com (redirect to cppstories.com)

  • Old URL still redirects. Covered under Bartek’s blog in 03_papers_and_deep_reads.md.

The five URLs you should be able to type from memory by end of Phase 0

  1. en.cppreference.com

  2. godbolt.org

  3. learncpp.com

  4. isocpp.org

  5. cppinsights.io

If you can’t yet, close this file and go bookmark them right now.

India-specific note: latency & offline

Several of these sites (godbolt, cppinsights, quick-bench) run on European/US infra and can feel sluggish on Indian broadband during peak evening hours (IST 19:00–23:00). Solutions:

  1. Local godbolt: You can docker pull compilerexplorer/compiler-explorer and run a local instance. Instructions at https://github.com/compiler-explorer/compiler-explorer. Overkill for solo learners; useful for corporate deployment.

  2. cppreference offline: Download the HTML archive as noted above. This alone eliminates 80% of network-dependent lookups.

  3. VPN: For the WG21 site (open-std.org) which occasionally has India-side routing issues, any commercial VPN or Cloudflare WARP resolves it.