diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/pure/hashes.nim | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/lib/pure/hashes.nim b/lib/pure/hashes.nim index 1c49b0317..d9f534670 100644 --- a/lib/pure/hashes.nim +++ b/lib/pure/hashes.nim @@ -51,8 +51,12 @@ runnableExamples: h = h !& hash(x.bar) result = !$h -## **Note:** If the type has a `==` operator, the following must hold: -## If two values compare equal, their hashes must also be equal. +## .. important:: Use `-d:nimPreviewHashRef` to +## enable hashing `ref`s. It is expected that this behavior +## becomes the new default in upcoming versions. +## +## .. note:: If the type has a `==` operator, the following must hold: +## If two values compare equal, their hashes must also be equal. ## ## See also ## ======== @@ -236,10 +240,14 @@ proc hash*[T](x: ptr[T]): Hash {.inline.} = assert cast[pointer](a[0].addr).hash == a[0].addr.hash hash(cast[pointer](x)) -when defined(nimEnableHashRef): +when defined(nimPreviewHashRef) or defined(nimdoc): proc hash*[T](x: ref[T]): Hash {.inline.} = ## Efficient `hash` overload. - runnableExamples: + ## + ## .. important:: Use `-d:nimPreviewHashRef` to + ## enable hashing `ref`s. It is expected that this behavior + ## becomes the new default in upcoming versions. + runnableExamples("-d:nimPreviewHashRef"): type A = ref object x: int let a = A(x: 3) @@ -247,7 +255,7 @@ when defined(nimEnableHashRef): assert ha != A(x: 3).hash # A(x: 3) is a different ref object from `a`. a.x = 4 assert ha == a.hash # the hash only depends on the address - runnableExamples: + runnableExamples("-d:nimPreviewHashRef"): # you can overload `hash` if you want to customize semantics type A[T] = ref object x, y: T |