whetstone_DSL/sprint48_plan.md

Sprint 48 Plan: C++ Semantic Raising from Core IR

Context

Sprint 48 implements the first production target backend for the new IR: modern C++. The goal is to generate reviewable, idiomatic C++ while preserving behavior contracts and memory safety intent from Rust lowering.

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Goals

1. Raise IR ownership semantics into RAII-centric C++
2. Generate idiomatic type, error, and algorithmic constructs
3. Produce compilable project artifacts (headers, sources, CMake)
4. Emit explicit risk annotations where semantics are weaker than Rust

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Steps

Step 709: Ownership mapping policy engine (unique_ptr/shared_ptr/value) (12 tests)

Step 710: Borrow semantics to references/views strategy (10 tests)

Step 711: Trait-to-interface/composition raising (10 tests)

Step 712: Generics/template raising policy (10 tests)

Step 713: Error model mapping (Result policy profiles) (10 tests)

Step 714: Async mapping strategy (coroutines/task runtime profiles) (10 tests)

Step 715: STL algorithm lifting from IR intent tags (8 tests)

Step 716: Build artifact generator (CMake targets + layout) (8 tests)

Step 717: whetstone_generate_cpp_from_ir MCP tool (8 tests)

Step 718: Sprint 48 integration summary + regression (8 tests)

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Output Profiles

• safe-first: explicit checks, conservative ownership, clearer diagnostics
• perf-first: low-overhead defaults, reduced abstraction layers
• interop-first: ABI-friendly shapes for mixed-language systems