Hi
On Thu, Mar 12, 2015 at 10:55 AM, Duncan Roe wrote:
> On Wed, Mar 11, 2015 at 06:55:16PM -0400, Vlad Gheorghiu wrote:
>> The following code fails to compile under latest cygwin, Windows 7,
>> g++4.9.2. Compiled with g++ -std=c++11 test.cpp. The compiler
>> complains that std::log2 is not a member of std.
>>
>> #include <cmath>
>> #include <iostream>
>>
>> int main()
>> {
>> auto x = std::log2(10);
>> std::cout << x << std::endl;
>> }
>>
>>
>> Verbatim error:
>>
>> g++ -std=c++11 test.cpp
>> test.cpp: In function 'int main()':
>> test.cpp:5:11: error: 'log2' is not a member of 'std'
>> auto x = std::log2(10);
>> ^
>> test.cpp:5:11: note: suggested alternative:
>> In file included from
>> /usr/lib/gcc/i686-pc-cygwin/4.9.2/include/c++/cmath:44:0,
>> from test.cpp:1:
>> /usr/include/math.h:305:15: note: ???log2???
>> extern double log2 _PARAMS((double));
>>
> FWIW, this program works fine under Linux / gcc4.8.2:
ISTR a discussion about some C++11 features being configured away due
to Cygwin's lack of some C library functions ("to_string not a member
of std"): https://sourceware.org/ml/cygwin/2015-01/msg00245.html
Your issue may be related (I'm guessing here because I don't have
Cygwin at hand right now).
Csaba
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