Re: The wording for lambdas

From:

Greg Herlihy <greghe@pacbell.net>

Newsgroups:

comp.std.c++

Date:

Mon, 15 Oct 2007 18:39:44 CST

Message-ID:

<1192347968.162711.101650@i13g2000prf.googlegroups.com>

On Oct 6, 11:47 am, restor <akrze...@interia.pl> wrote:

I have one concern about lambda wording (N2413). Will an introduction
of a new token <> not invalidate any code that fully specializes a
template, or instantiates a template that has default values for all
its parameters?

My understanding is that the code below would have two syntax errors:
-----------------------------------------------------------
template< typename T = int > struct Str{};

template<> struct Str<int> {}; // Error: Invalid Lambda definition
Str<> str; // The same

No, the proposed syntax for lambda definitions never has a "<>" appear
after an identifier or a keyword. Whereas the syntax for C++ templates
always has a "<>" appear after either an identifier or the "template"
keyword. Therefore a C++ compiler should be able to tell whether a
"<>" is part of lambda definition or part of a template specialization
based on what came before it.

Greg

--------------------------------------------------------
Should the standard not add a note in 14.3 that the token <> may be
split into two in some contexts, the same way that N1757 does?

No, there

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