在 std::enable_if 中添加等价检查时的模板推导问题

我正在尝试对不同的求和方法进行基准测试。我想使用如下界面

avx2_sum(container.begin(), container.end());

然而，我的尝试

enum class sum_algorithm: char{
    normal,
    kahan,
    twofold_fast //https://arxiv.org/pdf/1401.0248.pdf
};


template::value_type,
            std::enable_if_t<std::is_same<sum_t, double>::value && (algorithm_t == sum_algorithm::normal)> = true>
sum_t avx2_sum(const iterator_t begin, const iterator_t end) noexcept {
    // SIMD-parallel summation stage
    auto running_sums = _mm256_set1_pd(0);
    auto iterator_skip = 256/sizeof(sum_t);
    for (iterator_t it = begin; it + iterator_skip < end; it += iterator_skip){
        //TODO: flip to double load reduction
        running_sums = _mm256_add_pd(_mm256_load_pd(it), running_sums);
    }

    // Serial summation
    running_sums = _mm256_hadd_pd(running_sums, running_sums);
    running_sums = _mm256_hadd_pd(running_sums, running_sums);
    return _mm256_cvtsd_f64(running_sums);
}

产生以下结果：

error: no matching function for call to 'avx2_sum'
    std::cout << "avx2<float, normal>: " << accumulators::avx2_sum(float_arr.begin(), float_arr.end()) <<"\n";
                                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/rlfactory/dev/thommmj1/cppbenchmarks/cpp_utils/algorithms/cpu_accumulators.hpp:55:11: note: candidate template ignored: requirement 'std::is_same<float, double>::value' was not satisfied [with algorithm_t = accumulators::sum_algorithm::normal, iterator_t = __gnu_cxx::__normal_iterator > >, sum_t = float]
    sum_t avx2_sum(const iterator_t begin, const iterator_t end) noexcept {
          ^
/home/rlfactory/dev/thommmj1/cppbenchmarks/cpp_utils/algorithms/cpu_accumulators.hpp:71:11: note: candidate template ignored: substitution failure [with algorithm_t = accumulators::sum_algorithm::normal, iterator_t = __gnu_cxx::__normal_iterator > >, sum_t = float]: a non-type template parameter cannot have type 'std::enable_if_t<std::is_same<float, float>::value && ((sum_algorithm)'\x00' == sum_algorithm::normal)>' (aka 'void')
    sum_t avx2_sum(const iterator_t begin, const iterator_t end) noexcept {
          ^
/home/rlfactory/dev/thommmj1/cppbenchmarks/cpp_utils/algorithms/cpu_accumulators.hpp:87:11: note: candidate template ignored: requirement 'std::is_same<float, double>::value' was not satisfied [with algorithm_t = accumulators::sum_algorithm::normal, iterator_t = __gnu_cxx::__normal_iterator > >, sum_t = float]
    sum_t avx2_sum(const iterator_t begin, const iterator_t end) noexcept {
          ^
/home/rlfactory/dev/thommmj1/cppbenchmarks/cpp_utils/algorithms/cpu_accumulators.hpp:109:11: note: candidate template ignored: requirement 'std::is_same<float, float>::value && ((accumulators::sum_algorithm)'\x00' == sum_algorithm::kahan)' was not satisfied [with algorithm_t = accumulators::sum_algorithm::normal, iterator_t = __gnu_cxx::__normal_iterator > >, sum_t = float]
    sum_t avx2_sum(const iterator_t begin, const iterator_t end) noexcept {

我不明白如何扣除在这里不起作用。如果没有 algorithm_t 模板部分和检查，它工作得很好。也许是由于我的 using 声明？using algo = accumulators::sum_algorithm;