From 5e2c8fb089fdc5c1dfb36e22d25ae803fedee1ae Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@ionos.com>
Date: Wed, 22 Jan 2025 20:01:45 +0100
Subject: [PATCH] util/StringWithHash: add nullptr constructor

---
 src/util/StringWithHash.hxx | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/util/StringWithHash.hxx b/src/util/StringWithHash.hxx
index 5bf4c0a7..1d595712 100644
--- a/src/util/StringWithHash.hxx
+++ b/src/util/StringWithHash.hxx
@@ -26,6 +26,17 @@ struct StringWithHash {
 	explicit constexpr StringWithHash(std::string_view _value, std::size_t _hash) noexcept
 		:hash(_hash), value(_value) {}
 
+	/**
+	 * Construct a "nulled" instance, i.e. one where IsNull()
+	 * returns true.
+	 */
+	explicit constexpr StringWithHash(std::nullptr_t) noexcept
+		:value() {}
+
+	constexpr bool IsNull() const noexcept {
+		return value.data() == nullptr;
+	}
+
 	constexpr bool operator==(const StringWithHash &) const noexcept = default;
 };