safe_conversion.hpp

/*
  Copyright 2023 SINTEF AS
 
  This file is part of the Open Porous Media project (OPM).
 
  OPM is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
 
  OPM is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
 
  You should have received a copy of the GNU General Public License
  along with OPM.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_CUISTL_SAFE_CONVERSION_HPP
#define OPM_CUISTL_SAFE_CONVERSION_HPP
 
 
 
#include <cstddef>
#include <fmt/format.h>
#include <limits>
#include <opm/common/ErrorMacros.hpp>
#include <type_traits>
#include <cuda_runtime.h>
 

 
namespace Opm::gpuistl::detail
{

inline int
to_int(std::size_t s)
{
    static_assert(
        std::is_signed_v<int>,
        "Weird architecture or my understanding of the standard is flawed. Better have a look at this function.");
    static_assert(
        !std::is_signed_v<std::size_t>,
        "Weird architecture or my understanding of the standard is flawed. Better have a look at this function.");
 
    static_assert(
        sizeof(int) <= sizeof(std::size_t),
        "Weird architecture or my understanding of the standard is flawed. Better have a look at this function.");
 
 
    if (s > std::size_t(std::numeric_limits<int>::max())) {
        OPM_THROW(std::invalid_argument,
                  fmt::format("Trying to convert {} to int, but it is out of range. Maximum possible int: {}. ",
                              s,
                              std::numeric_limits<int>::max()));
    }
 
    // We know it will be in range here:
    return int(s);
}

__host__ __device__ inline std::size_t
to_size_t(int i)
{
    static_assert(
        std::is_signed_v<int>,
        "Weird architecture or my understanding of the standard is flawed. Better have a look at this function.");
    static_assert(
        !std::is_signed_v<std::size_t>,
        "Weird architecture or my understanding of the standard is flawed. Better have a look at this function.");
 
    static_assert(
        sizeof(int) <= sizeof(std::size_t),
        "Weird architecture or my understanding of the standard is flawed. Better have a look at this function.");
 
#if defined(__CUDA_ARCH__) || defined(__HIP_DEVICE_COMPILE__)
    assert(i >= int(0));
#else
    if (i < int(0)) {
        OPM_THROW(std::invalid_argument, fmt::format("Trying to convert the negative number {} to size_t.", i));
    }
#endif
 
    return std::size_t(i);
}
} // namespace Opm::gpuistl::detail
 
#endif