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Enum member std.range.primitives.isInfinite

Returns true if R is an infinite input range. An infinite input range is an input range that has a statically-defined enumerated member called empty that is always false, for example:

enum isInfinite(R) = !R.empty;
struct MyInfiniteRange
    enum bool empty = false;


import std.range : Repeat;
static assert(!isInfinite!(int[]));
static assert( isInfinite!(Repeat!(int)));

Returns `true` if `R` offers a slicing operator with integral boundaries
that returns a forward range type.

For finite ranges, the result of `opSlice` must be of the same type as the
original range type. If the range defines `opDollar`, then it must support

For infinite ranges, when <i>not</i> using `opDollar`, the result of
`opSlice` must be the result of <code class="lang-d"><span class="pln">take</span></code> or <code class="lang-d"><span class="pln">takeExactly</span></code> on the
original range (they both return the same type for infinite ranges). However,
when using `opDollar`, the result of `opSlice` must be that of the
original range type.

The following expression must be true for `hasSlicing` to be `true`:

isForwardRange!R && !isNarrowString!R && is(ReturnType!((R r) => r[1 .. 1].length) == size_t) && (is(typeof(lvalueOf!R[1 .. 1]) == R) || isInfinite!R) && (!is(typeof(lvalueOf!R[0 .. $])) || is(typeof(lvalueOf!R[0 .. $]) == R)) && (!is(typeof(lvalueOf!R[0 .. $])) || isInfinite!R || is(typeof(lvalueOf!R[0 .. $ - 1]) == R)) && is(typeof((ref R r) { static assert(isForwardRange!(typeof(r[1 .. 2])));


Andrei Alexandrescu, David Simcha, and Jonathan M Davis. Credit for some of the ideas in building this module goes to Leonardo Maffi.


Boost License 1.0.