不能从指针初始化c++ vector

Question

我想通过使用

来初始化一个c++ STL向量

template<class InputIt>
std::vector(InputIt first, InputIt last);

Cython中的构造函数。下面是一个简单的例子:

from libcpp.vector cimport vector
import numpy as np
cimport numpy as cnp
cnp.import_array()
def foo(double[::1] a):
cdef vector[double] vec = vector[double](&a[0], &a[0] + a.size)
# do something with vec..

但是，这会产生错误消息

from libcpp.vector cimport vector
def foo(double[::1] a):
cdef vector[double] vec = vector[double](&a[0], &a[0] + a.size)
^
------------------------------------------------------------
.ipython/cython/_cython_magic_c522d88d9553084771dd501620335f85a93b04ae.pyx:5:52: Cannot convert 'double *' to Python object
Error compiling Cython file:
------------------------------------------------------------
...
from libcpp.vector cimport vector
def foo(double[::1] a):
cdef vector[double] vec = vector[double](&a[0], &a[0] + a.size)
^
------------------------------------------------------------
.ipython/cython/_cython_magic_c522d88d9553084771dd501620335f85a93b04ae.pyx:5:45: Cannot assign type 'double *' to 'size_type

你知道我做错了什么吗?

Answer 1

正如在注释中提到的，您想要的构造函数在Cython中不可用。据我所知，Cython还不支持模板化构造函数。作为一种变通方法，您可以使用.assign()，即:

from libcpp.vector cimport vector
def foo(double[::1] a):
cdef vector[double] vec
vec.assign(&a[0], &a[0] + <size_t>a.size)
# do something with vec..