c++ - Maybe my understanding of [class.access]/7 isn't correct, but -

-

from [class.access]/7 have following sentence:

similarly, use of a::b base-specifier well-formed because d derived a, checking of base-specifiers must deferred until entire base-specifier-list has been seen.

class { protected:     struct b { }; }; struct d: a::b, { };

see live example clang. matter of fact, clang complains snippet, no deferment necessary.

class { protected:     struct b { }; }; struct d: a, a::b { };

why code not compile?

ps: gcc , vs21013 don't compile codes either.

this compiler bug. normative text of standard supports example. fact multiple compilers have same bug means part of standard tricky right.

there open bugs for gcc , for clang. note few related cases subtle differences between c++03 , c++11, far can tell, not one.

[class.access]/1.2 merely states

protected; is, name can used members , friends of class in declared, classes derived class, , friends (see 11.4).

and 11.4 not expand on this. using name b in class d derived class a. that's fine.


Comments

Post a Comment

Popular posts from this blog

c# - Better 64-bit byte array hash -

-
i need hash algorithm produces 64-bit hash code ( long ) fewer collisions string.gethashcode() , fast (no expensive calls cryptographic functions). here's implementation of fnv still shows 3% of collisions after testing 2 million random strings. need number way lower. void main() { const string chars = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz!#@$%^&*()_+}{\":?><,./;'[]0123456789\\"; const int n = 2000000; var random = new random(); var hashes = new hashset<long>(); int collisions = 0; for(int = 0; < n; i++) { var len = random.next(chars.length); var str = new char[len]; (int j = 0; j < len; j++) { str[j] = chars[random.next(chars.length)]; } var s = new string(str); if(!hashes.add(get64bithash( s ))) collisions++; } console.writeline("collision percentage after " + n + " random strings: " + ((doubl
Read more

webrtc - Which ICE candidate am I using and why? -

-
[questions in bold below] i have setup kurento media server 5.1.3 in datacenter behind firewall running os ubuntu 14.04. has 2 network cards: 222.222.222.222 (eth0 - private ip) 111.111.111.111 (eth1 - public ip) attached below sdp (setremotedescription) when browser connected kurento media server type: answer, sdp: v=0 o=- 5487318114793304426 0 in ip4 0.0.0.0 s=kurento media server c=in ip4 0.0.0.0 t=0 0 a=group:bundle audio video m=audio 59068 rtp/savpf 111 0 c=in ip4 111.111.111.111 a=rtpmap:111 opus/48000/2 a=rtpmap:0 pcmu/8000 a=sendrecv a=rtcp:59068 in ip4 111.111.111.111 a=rtcp-mux a=ssrc:669011897 cname:user39019747@host-6e83e4c2 a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time a=mid:audio b=as:20 a=ice-ufrag:ymdk a=ice-pwd:lylifk5ueqzpwm91ddj37e a=fingerprint:sha-256 ff:0f:81:8c:41:4e:b4:b6:c6:d8:36:f3:d6:5f:09:fd:5f:af:13:b3:9d:fc:12:66:ac:f3:56:d6:5b:0a:73:5d a=candidate:1 1 udp 2013266431 111.111.111.111 55239 typ host a=candidate:2 1 udp
Read more

php - Zend Framework / Skeleton-Application / Composer install issue -

-
i trying create zend framework application using skeleton in netbeans. when run composer install, following error message: "c:\php\php.exe" "c:\composer\composer.phar" "--ansi" "--no-interaction" "update" "--dev" using deprecated option "dev". dev packages installed default now. loading composer repositories package information updating dependencies (including require-dev) requirements not resolved installable set of packages. problem 1 - package requires php >=5.5 php version (5.4.42) not satisfy requirement. problem 2 - installation request zendframework/zendframework 2.5.1 -> satisfiable zendframework/zendframework[2.5.1]. - zendframework/zendframework 2.5.1 requires php >=5.5 -> php version (5.4.42) not satisfy requirement. done. apparently, zend framework only needs php 5.3+ contradicts above. need use php 5.4. my composer.json following: { "name": "
Read more