23 lines
833 B
Nim
23 lines
833 B
Nim
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import
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std/typetraits,
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./assign2
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func write*[T](s: var seq[T], v: openArray[T]) =
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# The Nim standard library is inefficient when copying simple types
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# into a seq: it will first zero-init the new memory then copy the items
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# one by one, when a copyMem would be sufficient - semantically, this
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# function performs the same thing as `add`, but similar to faststreams, from
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# where the `write` name comes from, it is much faster. Unfortunately, there's
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# no easy way to avoid the zero-init, but a smart compiler might be able
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# to elide it.
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when nimvm:
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s.add(v)
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else:
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if v.len > 0:
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let start = s.len
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s.setLen(start + v.len)
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when supportsCopyMem(T): # shortcut
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copyMem(addr s[start], unsafeAddr v[0], v.len * sizeof(T))
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else:
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assign(s.toOpenArray(start, s.high), v)
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