Function convert

CvPlot/ext/catch2/inc/catch.hpp:11315–11320

namespace {

    int32_t convert(float f) {
        static_assert(sizeof(float) == sizeof(int32_t), "Important ULP matcher assumption violated");
        int32_t i;
        std::memcpy(&i, &f, sizeof(f));
        return i;
    }

    int64_t convert(double d) {
        static_assert(sizeof(double) == sizeof(int64_t), "Important ULP matcher assumption violated");