Re: [Boost-bugs] [Boost C++ Libraries] #10439: Flyweight: now the constructor is explicit

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #10439: Flyweight: now the constructor is explicit
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-09-01 09:10:45

#10439: Flyweight: now the constructor is explicit
----------------------------------------------+-----------------------
  Reporter:  akim Demaille <akim.demaille@…>  |      Owner:  joaquin
      Type:  Bugs                             |     Status:  new
 Milestone:  To Be Determined                 |  Component:  flyweight
   Version:  Boost 1.56.0                     |   Severity:  Problem
Resolution:                                   |   Keywords:
----------------------------------------------+-----------------------

Comment (by Akim Demaille <akim.demaille@…>):

 The following also used to work up to 1.55, and is now broken.

 {{{
 $ cat foo.cc
 #include <string>
 #include <boost/flyweight.hpp>

 using string = boost::flyweight<std::string>;

 void foo(string) {}

 int main()
 {
   foo({});
 }
 $ clang++-mp-3.5 -std=c++11 -I /opt/local/include foo.cc
 foo.cc:10:3: error: no matching function for call to 'foo'
   foo({});
   ^~~
 foo.cc:6:6: note: candidate function not viable: cannot convert
 initializer list argument to 'string' (aka 'flyweight<std::string>')
 void foo(string) {}
      ^
 1 error generated.
 $ g++-mp-4.9 -std=c++11 -I /opt/local/include foo.cc
 foo.cc: In function 'int main()':
 foo.cc:10:9: error: converting to 'string {aka
 boost::flyweights::flyweight<std::basic_string<char> >}' from initializer
 list would use explicit constructor 'boost::flyweights::flyweight<T, Arg1,
 Arg2, Arg3, Arg4, Arg5>::flyweight(Args&& ...) [with Args = {}; T =
 std::basic_string<char>; Arg1 = boost::parameter::void_; Arg2 =
 boost::parameter::void_; Arg3 = boost::parameter::void_; Arg4 =
 boost::parameter::void_; Arg5 = boost::parameter::void_]'
    foo({});
          ^
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10439#comment:1>
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