CODEWITHSUNDEEP
c++visual-studioboost
user3196144
user3196144

Reputation: 307

Can't figure out why multi-precision calculation doesn't work for me using boost library

First I tried using GMP because boost documentation says it is faster but the gmp.h file was missing from boost library so I had to install GMP library and copy the gmp.h. After doing so I was getting external symbol Error when using mpz_int. So I decided to try cpp_int, copied the example from boost documentation and it worked. this is what I tried:

#include <boost/multiprecision/cpp_int.hpp>
#include <iostream>

int main()
{
   using namespace boost::multiprecision;

   int128_t v = 1;

   // Do some fixed precision arithmetic:
   for(unsigned i = 1; i <= 20; ++i)
      v *= i;

   std::cout << v << std::endl; // prints 20!

   // Repeat at arbitrary precision:
   cpp_int u = 1;
   for(unsigned i = 1; i <= 100; ++i)
      u *= i;

   std::cout << u << std::endl; // prints 100!

   return 0;
}

So then I created a factorial function in a Math class but now every time i use a variable from cpp_int library I receive that error: error LNK2019: unresolved external symbol __CrtDbgReportW referenced in function "void __cdecl std::_Debug_message(wchar_t const *,wchar_t const *,unsigned int)" (?_Debug_message@std@@YAXPB_W0I@Z)

Now every time I try to assign a new value to cpp_int variable I get that error, the weird thing is that the example worked and now the same example doesn't work for this project, but if I create a new project and use the same boost lib it works again.

Upvotes: 0

Views: 538

Answers (1)

shrike
shrike

Reputation: 4511

It's likely that one of the library you are using (probably the cpp_int library) wants to link with the Debug version of the Visual Studio runtime library. (Symbol __CrtDbgReportW is defined in the Debug version of the VS runtime library only.)

Make sure you compile your code for the appropriate target (Debug/Release), the third party libraries you are using are compiled for the same target, and that you link with the corresponding runtime library.

EDIT (after the comments you added earlier) :

Make sure you compile your code for the Static Debug version of the VC runtime library (aka libcpmtd.lib) :

In Visual Studio, open the Project Properties dialog and, in Configuration Properties -> C/C++ -> Code Generation, field Runtime Library, set to : Multi-threaded Debug (/MTd).

Note that any other library you link to your build must have the same setting.

Upvotes: 1

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