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2acb5743fa
The documentation is now generated from markdown. Samples are generated from the tutorial pages. Testing is done by a Python script which runs the tests for a large number of compilers. This version is not very developer-friendly - the Python scripts need ways of limiting what compilers they try to run. If you don't have 15 compilers installed, you won't be able to run the tests in this commit. Fix coming soon.
50 lines
1.4 KiB
C++
50 lines
1.4 KiB
C++
// This file was generated automatically
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// Bit sets
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//
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// If you want to use std::bitset or a similar library to use enums as keys into
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// a bit set, you need to know the number of bits at compile time. You can
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// easily automate this with Better Enums, even when constants are not declared
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// in increasing order.
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// We simply need to find the maximum value of any given enum type.
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#include <bitset>
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#include <enum.h>
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template <typename Enum>
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constexpr Enum max_loop(Enum accumulator, size_t index)
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{
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return
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index >= Enum::_size ? accumulator :
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Enum::_values()[index] > accumulator ?
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max_loop<Enum>(Enum::_values()[index], index + 1) :
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max_loop<Enum>(accumulator, index + 1);
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}
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template <typename Enum>
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constexpr Enum max()
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{
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return max_loop<Enum>(Enum::_values()[0], 1);
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}
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// And use that to declare a bit set template:
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template <typename Enum>
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using EnumSet = std::bitset<max<Enum>()._to_integral() + 1>;
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// Then rest is straightforward. The only issue is that, in $cxx11, it is
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// necessary to keep calling to_integral on the enums when passing them to
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// bitset functions. You may want to implement a more enum-friendly bit set
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// type, or overload unary operator -.
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ENUM(Channel, int, Red, Green, Blue)
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ENUM(Depth, int, TrueColor = 1, HighColor = 0)
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int main()
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{
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EnumSet<Channel> channels;
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EnumSet<Depth> depths;
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return 0;
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}
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