std :: vector中没有名为iterator_category的类型

Question

This code is giving an error :

vector<vector<bool> > revealed(vector<bool>(10, false), vector<bool>(10,false));

I am trying to define a 2D boolean array that has all elements as false by default.

The error is

.\stl_iterator_base_types.h|165|error: no type named 'iterator_category' in 'class std::vector<bool>'|

The error refers to line 165 of stl_iterator_base_types.h

162 template<typename _Iterator>
163 struct iterator_traits
164 {
165     typedef typename _Iterator::iterator_category iterator_category;
166     typedef typename _Iterator::value_type        value_type;
167     typedef typename _Iterator::difference_type   difference_type;
168     typedef typename _Iterator::pointer           pointer;
169     typedef typename _Iterator::reference         reference;
170 };

By the way, I am using Code::Blocks(with MinGW) as my IDE

Answer 1

You would initialize such a vector as follows

std::vector<std::vector<bool>> revealed(10, std::vector<bool>(10, false));

The reason is that the constructor overload you are trying to use for std::vector is

vector(size_type count, const T& value);

So you can see the first argument is the count, the second is the value. By this notion, you want the outer vector to be

vector(10, "vectors_of_length_10_wlth_all_false_values")
           ^

The way you signify the second argument is

std::vector<bool>(10, false)

The first argument for the outer vector is simply 10 because you want it to contain 10 of these vectors that have 10 false values.