Define a primitive data type: Difference between revisions
C++ version
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Line 10:
B : My_Type := A;
The compiler will omit bounds checking for the assignment of A to B above because both values are of My_Type. A cannot hold a value outside the range of 1..10, therefore the assignment cannot produce an out of bounds result.
==[[C plus plus|C++]]==
[[Category:C plus plus]]
'''Compiler:''' [[GCC]]
This class relies on implicit conversions to do most int operations; however the combined operations with assignment have to be coded explicitly.
#include <stdexcept>
class tiny_int
{
public:
tiny_int(int i):
value(i)
{
if (value < 1)
throw std::out_of_range("tiny_int: value smaller than 1");
if (value > 10)
throw std::out_of_range("tiny_int: value larger than 10");
}
operator int() const
{
return value;
}
tiny_int& operator+=(int i)
{
// by assigning to *this instead of directly modifying value, the
// constructor is called and thus the check is enforced
*this = value + i;
return *this;
}
tiny_int& operator-=(int i)
{
*this = value - i;
return *this;
}
tiny_int& operator*=(int i)
{
*this = value * i;
return *this;
}
tiny_int& operator/=(int i)
{
*this = value / i;
return *this;
}
tiny_int& operator<<=(int i)
{
*this = value << i;
return *this;
}
tiny_int& operator>>=(int i)
{
*this = value >> i;
return *this;
}
tiny_int& operator&=(int i)
{
*this = value & i;
return *this;
}
tiny_int& operator|=(int i)
{
*this = value | i;
return *this;
}
private:
unsigned char value; // we don't need more space
};
==[[Perl]]==
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