std::clamp
From cppreference.com
Defined in header
<algorithm>
|
||
template<class T>
constexpr const T& clamp( const T& v, const T& lo, const T& hi ); |
(1) | (since C++17) |
template<class T, class Compare>
constexpr const T& clamp( const T& v, const T& lo, const T& hi, Compare comp ); |
(2) | (since C++17) |
1) If
v
compares less than hi
, returns the larger of v
and lo
, otherwise returns the smaller of v
and hi
. Uses operator< to compare the values.
2) Same as (1), but uses
comp
to compare the values.
Contents |
[edit] Parameters
v | - | the value to clamp |
lo,hi | - | the boundaries to clamp v to
|
comp | - | comparison function object (i.e. an object that satisfies the requirements of Compare ) which returns true if lo is less than v and v is less than hi . The signature of the comparison function should be equivalent to the following: bool cmp(const Type1 &a, const Type2 &b); The signature does not need to have const &, but the function object must not modify the objects passed to it. |
Type requirements | ||
-
T must meet the requirements of LessThanComparable in order to use overloads (1).
|
[edit] Return value
Reference to v
if it is between the bounds, lo
if v
is smaller than lo
, and hi
if v
is larger than hi
.
If v
compares equivalent to either bound, returns v
.
[edit] Complexity
1) At most two comparisons
[edit] Possible implementation
First version |
---|
template<class T> constexpr const T& clamp( const T& v, const T& lo, const T& hi ) { return clamp( v, lo, hi, std::less<>() ); } |
Second version |
[edit] Notes
Capturing the result of std::clamp
by reference if one of the parameters is rvalue produces a dangling reference if that parameter is returned:
int n = -1; const int& r = std::clamp(n, 0, 255); // r is dangling
[edit] Example
This section is incomplete Reason: no example |
[edit] See also
returns the smaller of the given values (function template) |
|
returns the greater of the given values (function template) |