cpp-templates

cpp-templates is a skill for Codex from OutlineDriven/outline-driven-development. It costs 49 tokens per session (1,304 once invoked), scanned A, original, Apache-2.0.

A C++ guide for understanding template errors, adding rules that restrict which types a template accepts, and investigating slow template compilation.

In plain words
What is it for?
It is for diagnosing template errors, replacing older SFINAE techniques with C++20 concepts or requires-clauses, and profiling template-heavy builds.
Why use it?
It turns hard-to-read compiler messages into the failed substitution or requirement, and requires performance claims to be measured.

Skill for Codex

Written for Codex: agents/openai.yaml present.

Good fit It is for diagnosing template errors, replacing older SFINAE techniques with C++20 concepts or requires-clauses, and profiling template-heavy builds.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/outlinedriven/outline-driven-development/cpp-templates
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add OutlineDriven/outline-driven-development --skill cpp-templates
Clone the repo
git clone --depth 1 https://github.com/OutlineDriven/outline-driven-development

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for cpp-templates

README.md
[![agentmods](https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/cpp-templates/github.svg)](https://agentmods.dev/skills/outlinedriven/outline-driven-development/cpp-templates)
Your own site
<a href="https://agentmods.dev/skills/outlinedriven/outline-driven-development/cpp-templates"><img src="https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/cpp-templates/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for cpp-templates

Your own site · 80×15
<a href="https://agentmods.dev/skills/outlinedriven/outline-driven-development/cpp-templates"><img src="https://agentmods.dev/badge/skills/outlinedriven/outline-driven-development/cpp-templates.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,304 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00049 $0.01304
Opus 5 $0.00024 $0.00652
Sonnet 5 $0.00010 $0.00261
Haiku 4.5 $0.00005 $0.00130

Measured 3d ago against content hash ea735e1fb3f8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

cpp-templates scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.devin/skills/cpp-templates/SKILL.md · 60 lines

How it starts

The opening of the file, as written. The whole thing — 60 lines — stays where its author put it; the contents beside it link to each section on GitHub.

C++ templates

Contract

Field Bound contract
Trigger The user shows a long template error, asks how to constrain a template, asks SFINAE versus concepts, or reports that template-heavy translation units compile slowly.
Authority Read-only. The skill emits readings, constraint rewrites, and profiling commands to chat; the user edits the code. Rollback is not needed. No remote mutation.
Side effect Chat output. Profiling commands write trace files where the user runs them.
Done The failing instantiation is named with the substitution that failed, the proposed constraint compiles on the user's standard, and any compile-time claim carries a measurement command.

Inputs

  • Compiler, version, and -std=: required. Concepts need C++20; C++23 is the current standard and C++20 the floor.
  • The full diagnostic text: required for error reading.
  • The template and one call site: required for constraint work.
  • A build with compile_commands.json or a single reproducing TU: required for profiling.

Procedure

  1. Read the error from the bottom up. The first error: line names the user's call; the required from here (GCC) or in instantiation of (Clang) notes trace the chain; the last note names the type whose substitution failed. Shorten the chain with -ftemplate-backtrace-limit=N (GCC and Clang); with GCC add -fconcepts-diagnostics-depth=N for concept failures; with Clang add -fno-elide-type to print full types and -fdiagnostics-show-template-tree for a tree diff of the mismatch. Done when: the failing substitution and the call site are named.

  2. Write the constraint with concepts when the standard is C++20 or later:

    template <typename T> concept Arithmetic = std::is_arithmetic_v<T>;
    template <typename T> concept Container = requires(T c) {
        c.begin(); c.end(); c.size(); typename T::value_type;
    };
    template <Arithmetic T> T square(T x) { return x * x; }
    auto square(Arithmetic auto x) { return x * x; }
    template <typename T> requires Arithmetic<T> && (sizeof(T) >= 4)
    T big_square(T x) { return x * x; }
    

Read the full file on GitHub · 60 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 60 lines · 49 tokens per session scan A ea735e1fb3f8

Subscribe to this mod's changes

cpp-templates is a skill published in the GitHub repository OutlineDriven/outline-driven-development (52 stars, last pushed 3d ago), licensed Apache-2.0. It adds 49 tokens to every session and 1,304 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-06.

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