From 36b7870c982358f097333b0c12e005317ad6233c Mon Sep 17 00:00:00 2001
From: metagn <metagngn@gmail.com>
Date: Sat, 15 Feb 2025 09:12:30 +0300
Subject: [PATCH 1/4] match generic invocations to generic body types

---
 compiler/sigmatch.nim                | 17 +++++++++++++++++
 tests/overload/tgenericbodymatch.nim | 13 +++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 tests/overload/tgenericbodymatch.nim

diff --git a/compiler/sigmatch.nim b/compiler/sigmatch.nim
index 950ebe5196d66..885c85868a133 100644
--- a/compiler/sigmatch.nim
+++ b/compiler/sigmatch.nim
@@ -1745,6 +1745,23 @@ proc typeRel(c: var TCandidate, f, aOrig: PType,
     elif x.kind == tyGenericInst and concpt.kind == tyConcept:
       result = if concepts.conceptMatch(c.c, concpt, x, c.bindings, f): isGeneric
                else: isNone
+    elif x.kind == tyGenericBody:
+      # pretend we are matching against invocation type
+      let base = x[0]
+      if base == f[0]:
+        for i in 1..<f.len:
+          if i >= base.len-1: return
+          # least specific type that the parameter satisfies:
+          let constraint =
+            if base[i].genericParamHasConstraints:
+              base[i].genericConstraint
+            else:
+              # same as in liftParamType
+              newTypeS(tyAnything, c.c)
+          # match against constraint
+          let tr = typeRel(c, f[i], constraint, {trDontBind})
+          if tr <= isSubtype: return
+        result = isGeneric
     else:
       let genericBody = f[0]
       var askip = skippedNone
diff --git a/tests/overload/tgenericbodymatch.nim b/tests/overload/tgenericbodymatch.nim
new file mode 100644
index 0000000000000..2dd3e79c10997
--- /dev/null
+++ b/tests/overload/tgenericbodymatch.nim
@@ -0,0 +1,13 @@
+# issue #24688
+
+type
+  R[T, E] = object
+  A = object
+  B = object
+
+# Remove this overload to make it work
+func err[T](_: type R[T, void]): R[T, void] = discard
+
+func err(_: type R): R[A, B] = discard
+
+discard R.err()

From 74bb960212c0830462ece1bed05d097fffc2783f Mon Sep 17 00:00:00 2001
From: metagn <metagngn@gmail.com>
Date: Sat, 15 Feb 2025 09:14:19 +0300
Subject: [PATCH 2/4] do not match bodies to invocations at all

---
 compiler/sigmatch.nim | 20 +++-----------------
 1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/compiler/sigmatch.nim b/compiler/sigmatch.nim
index 885c85868a133..bface2398ba3b 100644
--- a/compiler/sigmatch.nim
+++ b/compiler/sigmatch.nim
@@ -1745,23 +1745,9 @@ proc typeRel(c: var TCandidate, f, aOrig: PType,
     elif x.kind == tyGenericInst and concpt.kind == tyConcept:
       result = if concepts.conceptMatch(c.c, concpt, x, c.bindings, f): isGeneric
                else: isNone
-    elif x.kind == tyGenericBody:
-      # pretend we are matching against invocation type
-      let base = x[0]
-      if base == f[0]:
-        for i in 1..<f.len:
-          if i >= base.len-1: return
-          # least specific type that the parameter satisfies:
-          let constraint =
-            if base[i].genericParamHasConstraints:
-              base[i].genericConstraint
-            else:
-              # same as in liftParamType
-              newTypeS(tyAnything, c.c)
-          # match against constraint
-          let tr = typeRel(c, f[i], constraint, {trDontBind})
-          if tr <= isSubtype: return
-        result = isGeneric
+    elif x.kind == tyGenericBody and f[0] == x:
+      # not specific enough
+      result = isNone
     else:
       let genericBody = f[0]
       var askip = skippedNone

From 6ce4e70f0efbfadcaadbd02b48490adfd03290b8 Mon Sep 17 00:00:00 2001
From: metagn <metagngn@gmail.com>
Date: Sat, 15 Feb 2025 10:21:55 +0300
Subject: [PATCH 3/4] update #5632 test

---
 tests/generics/tgenerics_issues.nim | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/generics/tgenerics_issues.nim b/tests/generics/tgenerics_issues.nim
index 3068a22f25be2..2cda8d3b518ad 100644
--- a/tests/generics/tgenerics_issues.nim
+++ b/tests/generics/tgenerics_issues.nim
@@ -741,7 +741,8 @@ block t1684:
 block t5632:
   type Option[T] = object
 
-  proc point[A](v: A, t: typedesc[Option[A]]): Option[A] =
+  # original issue test uses Option[A] instead
+  proc point[A](v: A, t: typedesc[Option]): Option[A] =
     discard
 
   discard point(1, Option)

From 04984ceab23ff4178a8b469473d6933f2449b1de Mon Sep 17 00:00:00 2001
From: metagn <metagngn@gmail.com>
Date: Sat, 29 Mar 2025 03:21:53 +0300
Subject: [PATCH 4/4] test arraymancer patch

---
 testament/important_packages.nim | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/testament/important_packages.nim b/testament/important_packages.nim
index 2471a2d113186..ed5344fe27f00 100644
--- a/testament/important_packages.nim
+++ b/testament/important_packages.nim
@@ -35,7 +35,9 @@ proc pkg(name: string; cmd = "nimble test -l"; url = "", useHead = true, allowFa
 
 pkg "alea"
 pkg "argparse"
-pkg "arraymancer", "nimble install -y; nimble uninstall -i -y nimcuda; nimble install nimcuda@0.2.1; nim c tests/tests_cpu.nim"
+pkg "arraymancer", "nimble install -y; nimble uninstall -i -y nimcuda; nimble install nimcuda@0.2.1; nim c tests/tests_cpu.nim",
+  # remove when https://github.com/mratsim/Arraymancer/pull/674 is merged
+  url = "https://github.com/metagn/Arraymancer"
 pkg "ast_pattern_matching", "nim c -r tests/test1.nim"
 pkg "asyncftpclient", "nimble compileExample"
 pkg "asyncthreadpool", "nimble test --mm:refc"