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Diffstat (limited to 'tests/objects/tobjcov.nim')
-rw-r--r-- | tests/objects/tobjcov.nim | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/tests/objects/tobjcov.nim b/tests/objects/tobjcov.nim new file mode 100644 index 000000000..a12f74702 --- /dev/null +++ b/tests/objects/tobjcov.nim @@ -0,0 +1,24 @@ +discard """ +action: compile +targets: "c" +""" + +# Covariance is not type safe: +# Note: `nim cpp` makes it a compile error (after codegen), even with: +# `var f = cast[proc (x: var TA) {.nimcall.}](cast[pointer](bp))`, which +# currently removes all the `cast` in cgen'd code, hence the compile error. + +type + TA = object of RootObj + a: int + TB = object of TA + b: array[0..5000_000, int] + +proc ap(x: var TA) = x.a = -1 +proc bp(x: var TB) = x.b[high(x.b)] = -1 + +# in Nim proc (x: TB) is compatible to proc (x: TA), +# but this is not type safe: +var f = cast[proc (x: var TA) {.nimcall.}](bp) +var a: TA +f(a) # bp expects a TB, but gets a TA |