Question

我有一个template函数，在变量中使用typename时总是出错。我有两个函数可以调用，它们是

template <>
void caffe_axpy<float>(const int N, const float alpha, const float* X,
    float* Y) { cblas_saxpy(N, alpha, X, 1, Y, 1); }

template <>
void caffe_axpy<double>(const int N, const double alpha, const double* X,
    double* Y) { cblas_daxpy(N, alpha, X, 1, Y, 1); }

因为它们可以是double或float，所以我将模板函数设为

template <typename Dtype>
void Blob<Dtype>::UpdateNew(Dtype decay, Dtype lr) {
  // We will perform update based on where the data is located.
  switch (data_->head()) {
  case SyncedMemory::HEAD_AT_CPU:
    // perform computation on CPU
    //this is using data and decay to update diff
    caffe_axpy<Dtype>(count_, (Dtype)decay,
        static_cast<const Dtype*>(data_->cpu_data()),
        static_cast<Dtype*>(diff_->mutable_cpu_data()));
    //this is using diff and lr to update data
    caffe_axpy<Dtype>(count_, (Dtype)lr,
        static_cast<const Dtype*>(diff_->cpu_data()),
        static_cast<Dtype*>(data_->mutable_cpu_data()));
    break;
  case SyncedMemory::HEAD_AT_GPU:
  case SyncedMemory::SYNCED:
#ifndef CPU_ONLY
    // perform computation on GPU
    //this is using data and decay to update diff
    caffe_gpu_axpy<Dtype>(count_, (Dtype)decay,
        static_cast<const Dtype*>(data_->gpu_data()),
        static_cast<Dtype*>(diff_->mutable_gpu_data()));
    //this is using diff and lr to update data
    caffe_gpu_axpy<Dtype>(count_, (float)lr,
        static_cast<const Dtype*>(diff_->gpu_data()),
        static_cast<Dtype*>(data_->mutable_gpu_data()));
#else
    NO_GPU;
#endif
    break;
  default:
    LOG(FATAL) << "Syncedmem not initialized.";
  }
}

如果我将所有以下行从Dtype更改为float，则没有错误。如果我使用Dtype，那么我有未定义的引用错误。

caffe_axpy<float>(count_, (float)decay,
            static_cast<const Dtype*>(data_->cpu_data()),
            static_cast<float*>(diff_->mutable_cpu_data()));
        //this is using diff and lr to update data
caffe_axpy<float>(count_, (float)lr,
            static_cast<const float*>(diff_->cpu_data()),
            static_cast<float*>(data_->mutable_cpu_data()));
 caffe_gpu_axpy<float>(count_, (float)decay,
            static_cast<const float*>(data_->gpu_data()),
            static_cast<float*>(diff_->mutable_gpu_data()));
        //this is using diff and lr to update data
caffe_gpu_axpy<float>(count_, (float)lr,
            static_cast<const float*>(diff_->gpu_data()),
            static_cast<float*>(data_->mutable_gpu_data()));

可能出现什么问题？

编辑：编译错误是

debug_debug/lib/libcaffe.so: undefined reference to `void caffe::caffe_axpy<unsigned int>(int, unsigned int, unsigned int const*, unsigned int*)'
.debug_debug/lib/libcaffe.so: undefined reference to `void caffe::caffe_gpu_axpy<unsigned int>(int, unsigned int, unsigned int const*, unsigned int*)'
.debug_debug/lib/libcaffe.so: undefined reference to `void caffe::caffe_gpu_axpy<int>(int, int, int const*, int*)'
.debug_debug/lib/libcaffe.so: undefined reference to `void caffe::caffe_axpy<int>(int, int, int const*, int*)'
collect2: error: ld returned 1 exit status

c ++中模板函数的未定义参考

0 个答案: