From 9383d29187d117d846f6db72cbcc980489b289c6 Mon Sep 17 00:00:00 2001
From: Harald Fernengel <harald.fernengel@here.com>
Date: Mon, 19 May 2025 13:03:04 +0200
Subject: [PATCH] Allow CancellationContext in hashes

A hash needs a hashing function and a way to determin equality.
Since we don't want to add a comparison operator, let's add
another helper so we can store CancellationContext in std::unordered_set
and friends.

Relates-To: MINOR
Signed-off-by: Harald Fernengel <harald.fernengel@here.com>
---
 .../olp/core/client/CancellationContext.h       | 17 +++++++++++++++++
 .../olp/core/client/CancellationContext.inl     |  5 +++++
 2 files changed, 22 insertions(+)

diff --git a/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.h b/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.h
index fbefe2979..1968730b4 100644
--- a/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.h
+++ b/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.h
@@ -83,6 +83,7 @@ class CORE_API CancellationContext {
  private:
   /// A helper for unordered containers.
   friend struct CancellationContextHash;
+  friend struct CancellationContextEquality;
 
   /**
    * @brief An implementation used to shared the `CancellationContext` instance.
@@ -126,6 +127,22 @@ struct CORE_API CancellationContextHash {
   size_t operator()(const CancellationContext& context) const;
 };
 
+/**
+ * @brief A helper for unordered containers for equality comparison
+ */
+struct CORE_API CancellationContextEquality {
+  /**
+   * @brief Checks equality for two `CancellationContext` instances.
+   *
+   * @param lhs The first `CancellationContext` instance.
+   * @param rhs The second `CancellationContext` instance.
+   *
+   * @return True if both refer to the same implementation; false otherwise.
+   */
+  bool operator()(const CancellationContext& lhs,
+                  const CancellationContext& rhs) const;
+};
+
 }  // namespace client
 }  // namespace olp
 
diff --git a/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.inl b/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.inl
index e19aeefb2..2d58fc903 100644
--- a/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.inl
+++ b/olp-cpp-sdk-core/include/olp/core/client/CancellationContext.inl
@@ -79,5 +79,10 @@ inline size_t CancellationContextHash::operator()(
       context.impl_);
 }
 
+inline bool CancellationContextEquality::operator()(
+    const CancellationContext& lhs, const CancellationContext& rhs) const {
+  return lhs.impl_ == rhs.impl_;
+}
+
 }  // namespace client
 }  // namespace olp