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Module std.meta
Templates to manipulate template parameter sequences (also known as alias sequences).
Some operations on alias sequences are built into the language,
such as S[i]
, which accesses the element at index i
in the
sequence. S[low .. high]
returns a new alias
sequence that is a slice of the old one.
For more information, see Compile-time Sequences.
Note: Several templates in this module use or operate on eponymous templates that take a single argument and evaluate to a boolean constant. Such templates are referred to as template predicates.
Category | Templates |
---|---|
Building blocks | Alias
AliasSeq
aliasSeqOf
|
Alias sequence filtering | Erase
EraseAll
Filter
NoDuplicates
Stride
|
Alias sequence type hierarchy | DerivedToFront
MostDerived
|
Alias sequence transformation | Repeat
Replace
ReplaceAll
Reverse
staticMap
staticSort
|
Alias sequence searching | allSatisfy
anySatisfy
staticIndexOf
|
Template predicates | templateAnd
templateNot
templateOr
staticIsSorted
|
Template instantiation | ApplyLeft
ApplyRight
Instantiate
|
References
Based on ideas in Table 3.1 from Modern C++ Design, Andrei Alexandrescu (Addison-Wesley Professional, 2001)
Templates
Name | Description |
---|---|
ApplyLeft
|
Partially applies Template by binding its first (left) or last (right) arguments to args. |
ApplyRight
|
Partially applies Template by binding its first (left) or last (right) arguments to args. |
Filter
|
Filters an AliasSeq using a template predicate. Returns an
AliasSeq of the elements which satisfy the predicate.
|
staticMap
|
Evaluates to AliasSeq!(F!(T[0]), F!(T[1]), ..., F!(T[$ - 1])) .
|
templateAnd
|
Combines several template predicates using logical AND, i.e. constructs a new predicate which evaluates to true for a given input T if and only if all of the passed predicates are true for T. |
templateNot
|
Negates the passed template predicate. |
templateOr
|
Combines several template predicates using logical OR, i.e. constructs a new predicate which evaluates to true for a given input T if and only at least one of the passed predicates is true for T. |
Manifest constants
Name | Type | Description |
---|---|---|
aliasSeqOf
|
Converts any foreach-iterable entity (e.g. an input range) to an alias sequence. | |
staticIndexOf
|
Returns the index of the first occurrence of args[0] in the
sequence args[1 .. $] . args may be types or compile-time values.
If not found, -1 is returned.
|
|
staticIsSorted
|
Checks if an AliasSeq is sorted according to cmp .
|
Aliases
Name | Type | Description |
---|---|---|
Alias
|
a
|
Allows alias ing of any single symbol, type or compile-time expression.
|
AliasSeq
|
TList
|
Creates a sequence of zero or more aliases. This is most commonly used as template parameters or arguments. |
allSatisfy
|
allSat!(F,T)
|
Tests whether all given items satisfy a template predicate, i.e. evaluates to
F!(T[0]) && F!(T[1]) && ... && F!(T[$ - 1]) .
|
anySatisfy
|
anySat!(F,T)
|
Tests whether any given items satisfy a template predicate, i.e. evaluates to
F!(T[0]) || F!(T[1]) || ... || F!(T[$ - 1]) .
|
DerivedToFront
|
TList
|
Returns an AliasSeq with the elements of TList sorted so that the most
derived types come first.
|
Erase
|
GenericErase!(T,TList)
|
Returns an AliasSeq created from TList with the first occurrence,
if any, of T removed.
|
EraseAll
|
GenericEraseAll!(T,TList)
|
Returns an AliasSeq created from TList with the all occurrences,
if any, of T removed.
|
Instantiate
|
Template!Params
|
Instantiates the given template with the given parameters. |
MostDerived
|
T
|
Returns the type from TList that is the most derived from type T. If none are found, T is returned. |
NoDuplicates
|
AliasSeq!(fst,EraseAllN!(fst.length,fst,snd))
|
Returns an AliasSeq created from TList with the all duplicate
types removed.
|
Repeat
|
AliasSeq!()
|
Creates an AliasSeq which repeats TList exactly n times.
|
Replace
|
GenericReplace!(T,U,TList)
|
Returns an AliasSeq created from TList with the first occurrence
of T, if found, replaced with U.
|
ReplaceAll
|
GenericReplaceAll!(T,U,TList)
|
Returns an AliasSeq created from TList with all occurrences
of T, if found, replaced with U.
|
Reverse
|
TList
|
Returns an AliasSeq created from TList with the order reversed.
|
staticSort
|
Seq
|
Sorts an AliasSeq using cmp .
|
Stride
|
AliasSeq!()
|
Selects a subset of Args by stepping with fixed stepSize over the sequence.
A negative stepSize starts iteration with the last element.
|
Authors
License
Copyright © 1999-2022 by the D Language Foundation | Page generated by ddox.