C++11 use in Chromium

I would be curious about the rationale behind this. Move semantics are a clear win in many situations, and I don't see any obvious pitfalls associated with them. I am curious especially about mere std::move; I'm aware that using rvalue references directly can be a bit confusing initially, and it makes sense to reduce their use.

Re: C++11 use in Chromium

#6

Post by pjmlp » Sat, Sep 27, 2014, 3:06 PM UTC

jcmakon wrote: post #4

Visual Studio limiting progress as always..

Visual Studio 2014 is already much better.

http://blogs.msdn.com/b/vcblog/archive/2014/08/21/c-11-14-fe...

Last time I checked, outside most C++ compilers were still catching up with C++11.

There are more C++ compilers out there than just clang and gcc. Even those aren't 100% compliant at library level, if I am not mistaken.

Re: C++11 use in Chromium

#7

Post by kps » Sat, Sep 27, 2014, 3:45 PM UTC

nhaehnle wrote: post #5

jesuslop wrote: post #2

Move semantics banned until revision.

I would be curious about the rationale behind this. Move semantics are a clear win in many situations, and I don't see any obvious pitfalls associated with them. I am curious especially about mere std::move; I'm aware that using rvalue references directly can be a bit confusing initially, and it makes sense to reduce their use.

std::move is a library function, and some Chrome targets don't have C++11-conformant libraries yet.

Re: C++11 use in Chromium

#8

Post by Suro » Sat, Sep 27, 2014, 4:06 PM UTC

pjmlp wrote: post #6

jcmakon wrote: post #4

Visual Studio limiting progress as always..

Visual Studio 2014 is already much better. http://blogs.msdn.com/b/vcblog/archive/2014/08/21/c-11-14-fe... Last time I checked, outside most C++ compilers were still catching up with C++11. There are more C++ compilers out there than just clang and gcc. Even those aren't 100% compliant at library level, if I am not mistaken.

Actually Clang is fully C++14 compliant, and already has some C++1z features, and gcc only need a few more patches.

Re: C++11 use in Chromium

#9

Post by reubenmorais » Sat, Sep 27, 2014, 4:39 PM UTC

kps wrote: post #7

nhaehnle wrote: post #5

Earlier quoted context omitted.

I would be curious about the rationale behind this. Move semantics are a clear win in many situations, and I don't see any obvious pitfalls associated with them. I am curious especially about mere std::move; I'm aware that using rvalue references directly can be a bit confusing initially, and it makes sense to reduce their use.

std::move is a library function, and some Chrome targets don't have C++11-conformant libraries yet.

move is just

    return static_cast(value);

Library support for std::move is not the reason it's disallowed. (If it is, that's just silly and someone should create a discussion thread).

Re: C++11 use in Chromium

#10

Post by gtremper » Sat, Sep 27, 2014, 6:18 PM UTC

reubenmorais wrote: post #9

kps wrote: post #7

Earlier quoted context omitted.

std::move is a library function, and some Chrome targets don't have C++11-conformant libraries yet.

move is just return static_cast (value); Library support for std::move is not the reason it's disallowed. (If it is, that's just silly and someone should create a discussion thread).

Its more than that. You can't put move-only types into std:: containers if the target doesn't have a C++11 support. There are many other pitfalls like this that are hard to notice until you try it on a pre-C++11 target.