bytedeco/javacpp

Add support variadic templates

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#81 opened on Feb 28, 2016

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 (4 comments) (0 reactions) (0 assignees)Java (4,279 stars) (620 forks)batch import
enhancementhelp wanted

Description

Add support for variadic templates

eg.

template <typename... Arguments> returntype functionname(Arguments... args);

or

template<typename ...Arguments> class classname;

Currently this throws an NPE:

Caused by: java.lang.NullPointerException
    at org.bytedeco.javacpp.tools.Parser.parameters(Parser.java:1366)
    at org.bytedeco.javacpp.tools.Parser.declarator(Parser.java:845)
    at org.bytedeco.javacpp.tools.Parser.function(Parser.java:1457)
    at org.bytedeco.javacpp.tools.Parser.declarations(Parser.java:2639)
    at org.bytedeco.javacpp.tools.Parser.group(Parser.java:2214)
    at org.bytedeco.javacpp.tools.Parser.declarations(Parser.java:2638)
    at org.bytedeco.javacpp.tools.Parser.namespace(Parser.java:2544)
    at org.bytedeco.javacpp.tools.Parser.declarations(Parser.java:2637)
    at org.bytedeco.javacpp.tools.Parser.parse(Parser.java:2713)
    at org.bytedeco.javacpp.tools.Parser.parse(Parser.java:2806)
    at org.bytedeco.javacpp.tools.Builder.parse(Builder.java:69)
    at org.bytedeco.javacpp.tools.Builder.build(Builder.java:625)
    at org.bytedeco.javacpp.tools.BuildMojo.execute(BuildMojo.java:226)```

Contributor guide

Tech stack
cppjava
Domain
toolingdeveloper experience
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
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.
mostly clear
Prerequisites
Basic knowledge of C++ templatesFamiliarity with JavaCC grammarUnderstanding of the javacpp parser (Parser.java)Java development environment setup
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
Investigate Parser.java at lines around 1366 and the parameter handling in the declarator method. Look at how non variadic templates are currently parsed and extend the grammar to handle variadic templates. Review any existing comments on this issue for insights. Consider adding test cases for the new syntax.