diff options
| -rw-r--r-- | lib/pure/collections/sequtils.nim | 7 | ||||
| -rw-r--r-- | lib/system.nim | 13 |
2 files changed, 13 insertions, 7 deletions
diff --git a/lib/pure/collections/sequtils.nim b/lib/pure/collections/sequtils.nim index eb9ff32c6..9c33b2eb6 100644 --- a/lib/pure/collections/sequtils.nim +++ b/lib/pure/collections/sequtils.nim @@ -83,6 +83,7 @@ runnableExamples: import std/private/since import macros +from typetraits import supportsCopyMem when defined(nimPreviewSlimSystem): import std/assertions @@ -1114,8 +1115,12 @@ template newSeqWith*(len: int, init: untyped): untyped = import std/random var seqRand = newSeqWith(20, rand(1.0)) assert seqRand[0] != seqRand[1] + type T = typeof(init) let newLen = len - var result = newSeq[typeof(init)](newLen) + when supportsCopyMem(T) and declared(newSeqUninit): + var result = newSeqUninit[T](newLen) + else: # TODO: use `newSeqUnsafe` when that's available + var result = newSeq[T](newLen) for i in 0 ..< newLen: result[i] = init move(result) # refs bug #7295 diff --git a/lib/system.nim b/lib/system.nim index b9dd7f143..3e7d84b1d 100644 --- a/lib/system.nim +++ b/lib/system.nim @@ -1615,11 +1615,12 @@ when notJSnotNims and defined(nimSeqsV2): when not defined(js): template newSeqImpl(T, len) = result = newSeqOfCap[T](len) - when defined(nimSeqsV2): - cast[ptr int](addr result)[] = len - else: - var s = cast[PGenericSeq](result) - s.len = len + {.cast(noSideEffect).}: + when defined(nimSeqsV2): + cast[ptr int](addr result)[] = len + else: + var s = cast[PGenericSeq](result) + s.len = len proc newSeqUninitialized*[T: SomeNumber](len: Natural): seq[T] {.deprecated: "Use `newSeqUninit` instead".} = ## Creates a new sequence of type `seq[T]` with length `len`. @@ -1640,7 +1641,7 @@ when not defined(js): var s = cast[PGenericSeq](result) s.len = len - proc newSeqUninit*[T](len: Natural): seq[T] = + func newSeqUninit*[T](len: Natural): seq[T] = ## Creates a new sequence of type `seq[T]` with length `len`. ## ## Only available for types, which don't contain |