<分区>
这段 C++ 代码无法编译。有人知道为什么吗？
#include <functional>
#include <algorithm>
#include <vector>
#include <iostream>
int main(int a, char** v) {
std::vector<uint32_t> v1 {1,2,3,4};
std::vector<uint32_t> v2 {0};
std::vector<uint32_t> v3 {5,4,3,11};
std::vector<uint32_t> v4 {10,11,2};
auto vector_is_subset = [] (const std::vector<uint32_t> a, const std::vector<uint32_t> b) -> bool {
std::sort(a.begin(), a.end());
std::sort(b.begin(), b.end());
return std::includes(a.begin(), a.end(), b.begin(), b.end());
};
std::vector<uint32_t> f {};
if (v1.empty() || v2.empty() || v3.empty() || v4.empty() ){
std::cout << "a vector is empty" << std::endl;
}
return 0;
}
我得到了以下输出
g++ a.cpp -std=c++14
在/usr/include/c++/7/algorithm:62:0 包含的文件中， 来自 a.cpp:2:
/usr/include/c++/7/bits/stl_algo.h: In instantiation of ‘void std::__insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’: /usr/include/c++/7/bits/stl_algo.h:1885:25: required from ‘void std::__final_insertion_sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’ /usr/include/c++/7/bits/stl_algo.h:1971:31: required from ‘void std::__sort(_RandomAccessIterator, _RandomAccessIterator, _Compare) [with _RandomAccessIterator = __gnu_cxx::__normal_iterator >; _Compare = __gnu_cxx::__ops::_Iter_less_iter]’ /usr/include/c++/7/bits/stl_algo.h:4836:18: required from ‘void std::sort(_RAIter, _RAIter) [with _RAIter = __gnu_cxx::__normal_iterator >]’ a.cpp:16:31: required from here /usr/include/c++/7/bits/stl_algo.h:1852:17: error: assignment of read-only location ‘__first.__gnu_cxx::__normal_iterator >::operator*()’ *__first = _GLIBCXX_MOVE(__val);