CppTemplateProgramming/27ExpressionTemplates/P630.ClassicTemplateArray.cpp at master · tch0/CppTemplateProgramming · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
#include <iostream>
#include <type_traits>
#include <cstddef>
#include <cassert>

template<typename T>
class SArray
{
private:
    T* storage;
    std::size_t storage_size;
protected:
    void init()
    {
        for (std::size_t idx = 0; idx < size(); ++idx)
        {
            storage[idx] = T();
        }
    }
    void copy(const SArray<T>& source)
    {
        assert(size() == source.size());
        for (std::size_t idx = 0; idx < size(); ++idx)
        {
            storage[idx] = source.storage[idx];
        }
    }
public:
    explicit SArray(std::size_t s) : storage(new T[s]), storage_size(s)
    {
        init();
    }
    SArray(const SArray<T>& source) : storage(new T[source.size()]), storage_size(source.size())
    {
        copy(source);
    }
    ~SArray()
    {
        delete [] storage;
    }
    SArray& operator=(const SArray<T>& source)
    {
        if (&source != this)
        {
            copy(source);
        }
        return *this;
    }
    std::size_t size() const
    {
        return storage_size;
    }
    const T& operator[](std::size_t idx) const
    {
        return storage[idx];
    }
    T& operator[](std::size_t idx)
    {
        return storage[idx];
    }
};

// operators
template<typename T>
SArray<T> operator+(const SArray<T>& a, const SArray<T>& b)
{
    assert(a.size() == b.size());
    SArray<T> res(a.size());
    for (std::size_t idx = 0; idx < a.size(); ++idx)
    {
        res[idx] = a[idx] + b[idx];
    }
    return res;
}

template<typename T>
SArray<T> operator*(const SArray<T>& a, const SArray<T>& b)
{
    assert(a.size() == b.size());
    SArray<T> res(a.size());
    for (std::size_t idx = 0; idx < a.size(); ++idx)
    {
        res[idx] = a[idx] * b[idx];
    }
    return res;
}

template<typename T>
SArray<T> operator+(const T& a, const SArray<T>& b)
{
    SArray<T> res(b.size());
    for (std::size_t idx = 0; idx < b.size(); ++idx)
    {
        res[idx] = a + b[idx];
    }
    return res;
}

template<typename T>
SArray<T> operator+(const SArray<T>& a, const T& b)
{
    SArray<T> res(a.size());
    for (std::size_t idx = 0; idx < a.size(); ++idx)
    {
        res[idx] = a[idx] + b;
    }
    return res;
}

template<typename T>
SArray<T> operator*(const T& a, const SArray<T>& b)
{
    SArray<T> res(b.size());
    for (std::size_t idx = 0; idx < b.size(); ++idx)
    {
        res[idx] = a * b[idx];
    }
    return res;
}

template<typename T>
SArray<T> operator*(const SArray<T>& a, const T& b)
{
    SArray<T> res(a.size());
    for (std::size_t idx = 0; idx < a.size(); ++idx)
    {
        res[idx] = a[idx] * b;
    }
    return res;
}
// ...

template<typename T>
void printArray(const SArray<T>& arr)
{
    assert(arr.size() > 0);
    std::cout << "SArray[" << arr.size() << "]: ";
    for (std::size_t i = 0; i < arr.size(); ++i)
    {
        std::cout << arr[i] << ", ";
    }
    std::cout << std::endl;
}

int main(int argc, char const *argv[])
{
    SArray<int> a(10);
    printArray(a);
    a = a + 1;
    a = a * 3;
    printArray(a);
    return 0;
}