Re: [Boost-users] A question on overloaded function? Can anyone with kindness help me?

Subject: Re: [Boost-users] A question on overloaded function? Can anyone with kindness help me?
From: fmingu (fmingu_at_[hidden])
Date: 2009-07-01 20:54:59

But how can I change the expression to be legal and usable?
 bind(&std::pow,constant(-1),bind(&IIPrimemap::size,var(primemapvec)));
I tried :
bind(&std::pow,constant(-1.0),bind<int>(&IIPrimemap::size,var(primemapvec)));
and 
bind(&std::pow,constant(-1.0),ret<int>(bind(&IIPrimemap::size,var(primemapvec))));
even 
bind(&std::pow,constant(-1.0),ll_dynamic_cast<int>(bind(&IIPrimemap::size,var(primemapvec))));
But the complier told me that:
cannot resolve overloaded function `pow' based on conversion to 
   type `unsigned int'
I do not know how to solve now.
Can anyone with kindness help me?

ÔÚ2009-07-01£¬"Steven Watanabe" <watanabesj_at_[hidden]> дµÀ£º
>AMDG
>
>fmingu wrote:
>> I use Dev-C++,and the snipet of the program is:
>> #pragma hdrstop
>> # include <iostream>
>> # include <vector>
>> # include <iterator>
>> # include "boost/math/common_factor.hpp"
>> # include "boost/lambda/lambda.hpp"
>> # include "boost/lambda/bind.hpp"
>> # include "boost/lambda/if.hpp"
>> # include "boost/lambda/casts.hpp"
>> # include "boost/lambda/construct.hpp"
>> # include "boost/lambda/loops.hpp"
>> # include "boost/lambda/switch.hpp"
>> # include "boost/tuple/tuple.hpp"
>> # include "boost/tuple/tuple_comparison.hpp"
>> # include <string>
>> # include <map>
>>  
>> using namespace std;
>> using namespace boost::lambda;
>> using namespace boost;
>>
>> void a(){
>>     std::cout<<std::pow(4,3);   
>>     return;
>> }   
>> ...............
>> but the complier told me that:
>>
>> main2test.cpp: In function `void a()':
>> main2test.cpp:69: call of overloaded `pow(int, int)' is ambiguous
>> F:/CB2009/Dev-Cpp/include/math.h:162: candidates are: double pow(double, double)
>> F:/CB2009/Dev-Cpp/include/c++/cmath:401:      float std::pow(float,  float)
>> F:/CB2009/Dev-Cpp/include/c++/cmath:410:                 long double 
>>    std::pow(long double, long double)
>> F:/CB2009/Dev-Cpp/include/c++/cmath:419:                 double 
>>    std::pow(double, int)
>> F:/CB2009/Dev-Cpp/include/c++/cmath:423:                 float std::pow(float, 
>>    int)
>> F:/CB2009/Dev-Cpp/include/c++/cmath:427:                 long double 
>>    std::pow(long double, int)
>>  
>> And in my computer, the C++ libraries includes are
>> F:\CB2009\Dev-Cpp\include\c++
>> F:\CB2009\Dev-Cpp\include\c++\mingw32
>> F:\CB2009\Dev-Cpp\include\c++\backward
>> F:\CB2009\Dev-Cpp\include
>> F:\CB2009\boost_1_34_1\boost_1_34_1
>> I do not know how to solve it.
>
>There is no overload of std::pow that takes two ints.
>You need to match one of the possible signatures exactly.
>
>> I do not use <math> or <cmath> yet.
>> Why the complier told me such files? And whether the two files are included in other files or not?
>>   
>
>Apparently cmath is included indirectly by some other header file.
>This is hardly an unusual occurrence in C++...
>
>> And can I use:
>> bind(&std::pow,constant(-1),bind(&IIPrimemap::size,var(primemapvec)));
>>   
>
>You can't pass the address of an overloaded function to
>a function template like bind without casting it to the
>correct function pointer type.
>
>> in the program? where :
>> typedef std::pair<int, int> IIPrimepair;
>> std::vector<IIPrimepair> primepairvec;
>>  
>> Can anyone with kindness help me? 
>
>In Christ,
>Steven Watanabe
>