[llvm] [llvm] Remove argument_type in std::hash specializations (NFC) (PR #165167)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/165167

The argument_type and result_type type aliases in std::hash are
deprecated in C++17 and removed in C++20.  This patch aligns two
specializations of ours with the C++ standard.


>From fb6b887679eff70aad3533f7c58830b8ef8abec3 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Wed, 22 Oct 2025 09:13:52 -0700
Subject: [PATCH] [llvm] Remove argument_type in std::hash specializations
 (NFC)

The argument_type and result_type type aliases in std::hash are
deprecated in C++17 and removed in C++20.  This patch aligns two
specializations of ours with the C++ standard.
---
 llvm/include/llvm/DebugInfo/PDB/PDBTypes.h      | 5 +----
 llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp | 5 +----
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h b/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h
index a64a2e888e9b9..7af2ff1290abe 100644
--- a/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h
+++ b/llvm/include/llvm/DebugInfo/PDB/PDBTypes.h
@@ -600,10 +600,7 @@ struct Variant {
 namespace std {
 
 template <> struct hash<llvm::pdb::PDB_SymType> {
-  using argument_type = llvm::pdb::PDB_SymType;
-  using result_type = std::size_t;
-
-  result_type operator()(const argument_type &Arg) const {
+  std::size_t operator()(const llvm::pdb::PDB_SymType &Arg) const {
     return std::hash<int>()(static_cast<int>(Arg));
   }
 };
diff --git a/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp b/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
index 93ae5483dedbb..7bef3a8f4d3ff 100644
--- a/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
+++ b/llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp
@@ -86,10 +86,7 @@ template <> struct llvm::DenseMapInfo<VariableID> {
 using VarLocInsertPt = PointerUnion<const Instruction *, const DbgRecord *>;
 
 template <> struct std::hash<VarLocInsertPt> {
-  using argument_type = VarLocInsertPt;
-  using result_type = std::size_t;
-
-  result_type operator()(const argument_type &Arg) const {
+  std::size_t operator()(const VarLocInsertPt &Arg) const {
     return std::hash<void *>()(Arg.getOpaqueValue());
   }
 };