Some Eclipse Foundation services are deprecated, or will be soon. Please ensure you've read this important communication.

Bug 338611

Summary:	Parser error when using decltype
Product:	[Tools] CDT	Reporter:	Nathan Ridge <zeratul976>
Component:	cdt-indexer	Assignee:	Sergey Prigogin <eclipse.sprigogin>
Status:	RESOLVED FIXED	QA Contact:	Markus Schorn <mschorn.eclipse>
Severity:	normal
Priority:	P3	CC:	cdtdoug, eclipse.sprigogin, yevshif
Version:	8.0
Target Milestone:	8.1.1
Hardware:	All
OS:	All
Whiteboard:
Bug Depends on:	299911
Bug Blocks:

Description Nathan Ridge

2011-03-01 20:17:11 EST

Here is test.hpp:

template <typename T>
class A {};
    
template <typename T>
A<T> h(T);

template <typename T>
auto g(T t) -> decltype(h(t));


Here is test.cpp:

#include "test.hpp"

void f()
{
    g(0);  // ERROR HERE
}


The parser gives the following error:

Invalid arguments ' Candidates are: ? g(#0) '

The code compiles fine with g++ >= 4.4

Comment 1 Nathan Ridge

2011-03-01 20:23:56 EST

I should note that if I copy-and-paste the contents of test.hpp into test.cpp in place of the #include, the error goes away. This is not the first time I've seen this behaviour, and I am very curious as to why it happens.

Comment 2 Markus Schorn

2011-03-02 04:30:52 EST

Currently we cannot properly store dependent types involving decltype.

Comment 3 Nathan Ridge

2011-03-30 20:20:59 EDT

I'm not sure whether this (and the bug it depends on) is planned to be fixed for 8.0, but if not, would it be possible to disable the generation of "Invalid arguments ..." error bindings for functions where the parser is unable to deduce to return type or argument types?

I think users would rather the parser fail to report a few legitimate errors, than report errors for valid code.

Comment 4 Sergey Prigogin

2012-08-18 23:31:03 EDT

Fixed together with bug 299911.