Subject: Re: [boost] [endian] Project not maintained
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2016-04-04 11:12:39
On 2016-04-04 16:55, Peter Dimov wrote:
> Andrey Semashev wrote:
>
>> I think it's not Boost.Endian's job to deal with FP implementations.
>> Or integer implementations, for that matter.
>
> Dealing with different implementations is technically outside the
> charter of an "endianness" library. The end goal, however, is to let one
> read and write integers and floats in non-native formats. And when those
> non-native formats have a representation that is not a simple byteswap
> away from the native one, it would be kind of useful if the library
> still worked.
IMHO, if you need something more than a byte swap then you need a
different library.
>> The interface can be defined to require a certain implementation of
>> float or to simply ignore the implementation and consider input as
>> opaque sequence of bytes. The implementation of that interface should
>> just reorder bytes in that sequence, as requested, and do nothing more
>> than that.
>
> The interface could obviously be defined in various ways. What specific
> interface do you suggest?
Well, in some of the projects I work on we have something as simple as:
void write_be32(std::uint32_t n, void* p);
std::uint32_t read_be32(const void* p);
// etc.
template< typename T, std::size_t Size = sizeof(T) >
struct big_endian;
// Specializations for different values of Size
template< typename T >
struct big_endian< T, 4 >
{
static void write(T n, void* p)
{
write_be32(n, p);
}
static T read(const void* p)
{
return read_be32(p);
}
};
// ditto for little endian
As simplistic and error prone as it may look, this basic interface is
enough to build higher level and more specialized tools upon.