Re: [boost] [type_traits] is_constructible, ... when decltype is supported?

Subject: Re: [boost] [type_traits] is_constructible, ... when decltype is supported?
From: Vicente Botet (vicente.botet_at_[hidden])
Date: 2011-06-07 13:15:05

Mathias Gaunard-2 wrote:
> 
> On 05/06/2011 22:32, Vicente Botet wrote:
> 
>> We can use it as the return type of the test function. FOr example to
>> test
>> if T can be constructed with two parameters A1, A2
>>
>> decltype((T(declval<A1>(),declval<A2>()), true_type())) test(int);
>> false_type test(...);
> 
> You realize you can do the same thing with sizeof in C++03, when 
> BOOST_NO_SFINAE_EXPR is not defined?
> 
> Also you shouldn't use decltype directly in the return type if you want 
> portability, it caused mangling problems with some GCC versions.
> 
> Attached is a C++03-compatible version.
> 
> 

Hi, glad to see that a C++03 version works. Unfortunately it seems that only
gcc since 4.4 supports this. 

Anyway I agree that your solution should be more portable. 

Best,
Vicente

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