tmp/tmpvu4_wnaw/{from.md → to.md}
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| 1 |
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### Integral powers of 2 <a id="bit.pow.two">[[bit.pow.two]]</a>
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``` cpp
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template<class T>
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constexpr bool has_single_bit(T x) noexcept;
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```
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*Constraints:* `T` is an unsigned integer type [[basic.fundamental]].
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*Returns:* `true` if `x` is an integral power of two; `false` otherwise.
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``` cpp
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template<class T>
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constexpr T bit_ceil(T x);
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```
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Let N be the smallest power of 2 greater than or equal to `x`.
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*Constraints:* `T` is an unsigned integer type [[basic.fundamental]].
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*Preconditions:* N is representable as a value of type `T`.
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*Returns:* N.
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*Throws:* Nothing.
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*Remarks:* A function call expression that violates the precondition in
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the *Preconditions:* element is not a core constant
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expression [[expr.const]].
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``` cpp
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template<class T>
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constexpr T bit_floor(T x) noexcept;
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```
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*Constraints:* `T` is an unsigned integer type [[basic.fundamental]].
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*Returns:* If `x == 0`, `0`; otherwise the maximal value `y` such that
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`has_single_bit(y)` is `true` and `y <= x`.
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``` cpp
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template<class T>
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constexpr T bit_width(T x) noexcept;
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```
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*Constraints:* `T` is an unsigned integer type [[basic.fundamental]].
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*Returns:* If `x == 0`, `0`; otherwise one plus the base-2 logarithm of
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`x`, with any fractional part discarded.
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