48 lines
1.2 KiB
Nim
48 lines
1.2 KiB
Nim
import
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unittest, math,
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../../stew/ranges/[stackarrays, ptr_arith]
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suite "Stack arrays":
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test "Basic operations work as expected":
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var arr = allocStackArray(int, 10)
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check:
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type(arr[0]) is int
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arr.len == 10
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# all items should be initially zero
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for i in arr: check i == 0
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for i in 0 .. arr.high: check arr[i] == 0
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arr[0] = 3
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arr[5] = 10
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arr[9] = 6
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check:
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sum(arr.toOpenArray) == 19
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arr[5] == 10
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arr[^1] == 6
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cast[ptr int](shift(addr arr[0], 5))[] == 10
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test "Allocating with a negative size throws a RangeError":
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expect RangeError:
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var arr = allocStackArray(string, -1)
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test "The array access is bounds-checked":
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var arr = allocStackArray(string, 3)
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arr[2] = "test"
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check arr[2] == "test"
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expect RangeError:
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arr[3] = "another test"
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test "proof of stack allocation":
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proc fun() =
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# NOTE: has to be inside a proc otherwise x1 not allocated on stack.
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var x1 = 0
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var arr = allocStackArray(int, 3)
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check:
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# stack can go either up or down, hence `abs`.
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# 1024 should be large enough (was 312 on OSX).
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abs(cast[int](x1.addr) - cast[int](addr(arr[0]))) < 1024
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fun()
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