glideapps/quicktype

C++: use different integer type

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#2180 opened on Feb 16, 2023

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 (2 comments) (2 reactions) (0 assignees)TypeScript (10,867 stars) (968 forks)batch import
C++customizationgood first issue

Description

When using a JSON Schema to generate C++ code, the generated class always uses int64_t for integer properties. In my other code this frequently leads to compiler warnings when I want to assign an integer property value to a C++ int, because the compiler warns about casts from int64_t to int (because we build with -Wc++11-narrowing and -Wshorten-64-to-32).

Is there a way to specify the C++ data type that should be used for a property? Then I could explicitly change the generated type to int (or short or char) where necessary.

Contributor guide

Tech stack
cpptypescript
Domain
tooling
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
C++JSON Schemaquicktype basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
50
Research direction
Investigate the C++ code generation module in quicktype (e.g., `src/quicktype core/language/Cpp.ts`). Look for existing mechanisms for type customization in other languages (e.g., Python's `type mapping`). Consider adding a new option to allow the user to specify the integer type via schema annotations or a command line flag. Review the discussion in the issue comments for any additional context.