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1 int return_six()
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2 {
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3 return 6;
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4 }
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5
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6 int add_int(int a, int b)
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7 {
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8 return a+b;
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9 }
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10
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11 int sub_int(int a, int b)
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12 {
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13 return a-b;
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14 }
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15
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16 alias int function(int,int) binfn_t;
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17
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18 int binop_int(binfn_t op, int a, int b)
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19 {
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20 return op(a,b);
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21 }
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22
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23 binfn_t get_binop_int(char op)
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24 {
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25 binfn_t fn;
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26 if (op == '+')
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27 fn = &add_int;
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28 else if (op == '-')
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29 fn = &sub_int;
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30 return fn;
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31 }
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32
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33 extern(C) float mul_float(float a, float b)
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34 {
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35 return a * b;
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36 }
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37
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38 void function_pointers()
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39 {
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40 int function() fn = &return_six;
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41 assert(fn() == 6);
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42
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43 binfn_t binfn = &add_int;
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44 assert(binfn(4,1045) == 1049);
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45
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46 assert(binop_int(binfn, 10,656) == 666);
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47
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48 binfn = get_binop_int('+');
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49 assert(binop_int(binfn, 10,100) == 110);
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50 binfn = get_binop_int('-');
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51 assert(binop_int(binfn, 10,100) == -90);
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52
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53 {
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54 auto ffn = &mul_float;
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55 float ftmp = mul_float(2.5,5);
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56 assert(ftmp == 12.5);
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57 assert(ftmp > 12.49 && ftmp < 12.51);
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58 }
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59 }
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60
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61 void main()
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62 {
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63 printf("Function pointer test\n");
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64 function_pointers();
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65 printf(" SUCCESS\n");
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66 }
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