I have written a short program utilising boost::float128 together with tux Eigen which successfully compiles and runs using g++, however it fails when I use icc.

The compiler error is

/home/alex/boost/boost_1_71_0/boost/multiprecision/float128.hpp(727): error: no suitable constructor exists to convert from "const _Quad" to "boost::multiprecision::number<boost::multiprecision::backends::float128_backend, boost::multiprecision::et_off>"

static number_type (min)() BOOST_NOEXCEPT { return BOOST_MP_QUAD_MIN; }

How can I resolve this?

My example code is;

#include <iostream>

#include <cmath>

#include <Eigen/Dense>

#include <Eigen/Eigenvalues>

#include <iomanip>

#include <boost/cstdfloat.hpp>

#include <boost/multiprecision/float128.hpp>

#include <boost/math/special_functions.hpp>

#include <boost/math/constants/constants.hpp>

#include <quadmath.h>

#define BOOST_MP_USE_QUAD

using namespace Eigen;

using namespace std;

int main(){

typedef Matrix<complex<boost::multiprecision::float128>, Dynamic, Dynamic> MatrixXcmp;

MatrixXcmp C = MatrixXcmp::Random(8,8);

cout<<setprecision(128)<<C<<endl<<endl;

ComplexEigenSolver<MatrixXcmp> ces;

ces.compute(C);

return 0;

}

It only fails compilation when I put in the line 'ces.compute(C);'.

I compile with

icpc quadtest.cpp -std=c++14 -Qoption,cpp,--extended_float_type -O2 -DMKL_LP64 -lmkl_intel_lp64 -fp-model precise -lmkl_sequential -lmkl_core -lpthread -lm -ldl -lquadmath

Many thanks in advance,

Alex