Appender

Implements an output range that appends data to an array. This is recommended over array ~= data when appending many elements because it is more efficient. Appender maintains its own array metadata locally, so it can avoid the performance hit of looking up slice capacity for each append.

struct Appender (

) if (

isDynamicArray!A

) {

this(A arr);

void reserve(size_t newCapacity);

size_t capacity [@property getter];

size_t length [@property getter];

inout(T)[] data [@property getter];

inout(T)[] opSlice [@property getter];

void put(U item);

void put(Range items);

alias opOpAssign(string op : "~") = put;

static if(isMutable!T)

void clear();

static if(isMutable!T)

void shrinkTo(size_t newlength);

string toString();

struct FormatSpec(Char) via import std.format.spec : FormatSpec;;

template toString(Writer);

}

Constructors

this this(A arr): Constructs an Appender with a given array. Note that this does not copy the data. If the array has a larger capacity as determined by arr.capacity, it will be used by the appender. After initializing an appender on an array, appending to the original array will reallocate.

Members

Aliases

opOpAssign alias opOpAssign(string op : "~") = put: Appends to the managed array.

Functions

clear void clear(): Clears the managed array. This allows the elements of the array to be reused for appending.
put void put(U item): Appends item to the managed array. Performs encoding for char types if A is a differently typed char array.
put void put(Range items): Appends an entire range to the managed array. Performs encoding for char elements if A is a differently typed char array.
reserve void reserve(size_t newCapacity): Reserve at least newCapacity elements for appending. Note that more elements may be reserved than requested. If newCapacity <= capacity, then nothing is done.
shrinkTo void shrinkTo(size_t newlength): Shrinks the managed array to the given length.
toString string toString(): Gives a string in the form of Appender!(A)(data).

Properties

capacity size_t capacity [@property getter]
data inout(T)[] data [@property getter]: Use opSlice() from now on.
length size_t length [@property getter]
opSlice inout(T)[] opSlice [@property getter]

Templates

toString template toString(Writer): A general handler for format strings.

Parameters

A: the array type to simulate.

Examples

auto app = appender!string();
string b = "abcdefg";
foreach (char c; b)
    app.put(c);
assert(app[] == "abcdefg");

int[] a = [ 1, 2 ];
auto app2 = appender(a);
app2.put(3);
assert(app2.length == 3);
app2.put([ 4, 5, 6 ]);
assert(app2[] == [ 1, 2, 3, 4, 5, 6 ]);