std:: valarray
|
Defined in header
<valarray>
|
||
|
template
<
class
T
>
class valarray ; |
||
std::valarray
is the class for representing and manipulating arrays of values. It supports element-wise mathematical operations and various forms of generalized subscript operators, slicing and indirect access.
Notes
std::valarray
and helper classes are defined to be free of certain forms of aliasing, thus allowing operations on these classes to be optimized similar to the effect of the keyword
restrict
in the C programming language. In addition, functions and operators that take
valarray
arguments are allowed to return proxy objects to make it possible for the compiler to optimize an expression such as
v1
=
a
*
v2
+
v3
;
as a single loop that executes
v1
[
i
]
=
a
*
v2
[
i
]
+
v3
[
i
]
;
avoiding any temporaries or multiple passes. However,
expression templates
make the same optimization technique available for any C++ container, and the majority of numeric libraries prefer expression templates to valarrays for flexibility. Some C++ standard library implementations use expression templates to implement efficient operations on
std::valarray
(e.g. GNU libstdc++ and LLVM libc++). Only rarely are valarrays optimized any further, as in e.g.
Intel Integrated Performance Primitives
.
Template parameters
| T | - | the type of the elements. The type must meet the NumericType requirements |
Member types
| Member type | Definition |
value_type
|
T
|
Member functions
|
constructs new numeric array
(public member function) |
|
|
destructs the numeric array
(public member function) |
|
|
assigns the contents
(public member function) |
|
|
get/set valarray element, slice, or mask
(public member function) |
|
|
applies a unary arithmetic operator to each element of the valarray
(public member function) |
|
|
applies compound assignment operator to each element of the valarray
(public member function) |
|
|
swaps with another valarray
(public member function) |
|
|
returns the size of valarray
(public member function) |
|
|
changes the size of valarray
(public member function) |
|
|
calculates the sum of all elements
(public member function) |
|
|
returns the smallest element
(public member function) |
|
|
returns the largest element
(public member function) |
|
|
zero-filling shift the elements of the valarray
(public member function) |
|
|
circular shift of the elements of the valarray
(public member function) |
|
|
applies a function to every element of a valarray
(public member function) |
Non-member functions
|
(C++11)
|
specializes the
std::swap
algorithm
(function template) |
|
(C++11)
|
overloads
std::begin
(function template) |
|
(C++11)
|
specializes
std::end
(function template) |
|
applies binary operators to each element of two valarrays, or a valarray and a value
(function template) |
|
|
compares two valarrays or a valarray with a value
(function template) |
|
|
applies the function
abs
to each element of valarray
(function template) |
|
Exponential functions |
|
|
applies the function
std::exp
to each element of valarray
(function template) |
|
|
applies the function
std::log
to each element of valarray
(function template) |
|
|
applies the function
std::log10
to each element of valarray
(function template) |
|
Power functions |
|
|
applies the function
std::pow
to two valarrays or a valarray and a value
(function template) |
|
|
applies the function
std::sqrt
to each element of valarray
(function template) |
|
Trigonometric functions |
|
|
applies the function
std::sin
to each element of valarray
(function template) |
|
|
applies the function
std::cos
to each element of valarray
(function template) |
|
|
applies the function
std::tan
to each element of valarray
(function template) |
|
|
applies the function
std::asin
to each element of valarray
(function template) |
|
|
applies the function
std::acos
to each element of valarray
(function template) |
|
|
applies the function
std::atan
to each element of valarray
(function template) |
|
|
applies the function
std::atan2
to a valarray and a value
(function template) |
|
Hyperbolic functions |
|
|
applies the function
std::sinh
to each element of valarray
(function template) |
|
|
applies the function
std::cosh
to each element of valarray
(function template) |
|
|
applies the function
std::tanh
to each element of valarray
(function template) |
|
Helper classes
|
BLAS-like slice of a valarray: starting index, length, stride
(class) |
|
|
proxy to a subset of a valarray after applying a slice
(class template) |
|
|
generalized slice of a valarray: starting index, set of lengths, set of strides
(class) |
|
|
proxy to a subset of a valarray after applying a gslice
(class template) |
|
proxy to a subset of a valarray after applying a boolean mask
operator[]
(class template) |
|
proxy to a subset of a valarray after applying indirect
operator[]
(class template) |
Deduction guides (since C++17)
See also
|
(parallelism TS v2)
|
data-parallel vector type
(class template) |
|
(parallelism TS v2)
|
data-parallel type with the element type bool
(class template) |