u/string_list: Add contains function

src/xrt/auxiliary/util/u_string_list.cpp

@@ -98,6 +98,12 @@ u_string_list_append_unique(struct u_string_list *usl, const char *str)
 	}
 }
 
+bool
+u_string_list_contains(struct u_string_list *usl, const char *str)
+{
+	return usl->list.contains(str);
+}
+
 void
 u_string_list_destroy(struct u_string_list **list_ptr)
 {

src/xrt/auxiliary/util/u_string_list.h

@@ -84,6 +84,19 @@ u_string_list_append(struct u_string_list *usl, const char *str);
 int
 u_string_list_append_unique(struct u_string_list *usl, const char *str);
 
+/*!
+ * @brief Check if the string is in the list.
+ *
+ * (Comparing string contents, not just pointers)
+ *
+ * @param usl self pointer
+ * @param str a non-null, null-terminated string.
+ *
+ * @return true if the string is in the list.
+ */
+bool
+u_string_list_contains(struct u_string_list *usl, const char *str);
+
 /*!
  * @brief Destroy a string list.
  *

src/xrt/auxiliary/util/u_string_list.hpp

@@ -107,6 +107,30 @@ public:
 			push_back(elt);
 		}
 	}
+
+	/*!
+	 * @brief Check if the string is in the list.
+	 *
+	 * (Comparing string contents, not just pointers)
+	 *
+	 * @param str a non-null, null-terminated string.
+	 *
+	 * @return true if the string is in the list.
+	 */
+	bool
+	contains(const char *str)
+	{
+		if (str == nullptr) {
+			throw std::invalid_argument("Cannot pass a null pointer");
+		}
+		std::string needle{str};
+		auto it = std::find_if(vec.begin(), vec.end(), [needle](const char *elt) { return needle == elt; });
+		if (it != vec.end()) {
+			return true;
+		}
+		return false;
+	}
+
 	/*!
 	 * @brief Append a new string to the list if it doesn't match any existing string.
 	 *