From 5ff15443e9160d2669ee9f54a3cefd0c43537320 Mon Sep 17 00:00:00 2001
From: Peter Nelson <peter1138@openttd.org>
Date: Wed, 21 Apr 2021 13:42:30 +0100
Subject: [PATCH] Cleanup: Replace single-use Pair struct with std::pair.

This struct is defined in geometry_type but not used by any geometry-related
code, only for subsidy code where both parameters are cast from int to
NewsReferenceType.
---
 src/core/geometry_type.hpp |  6 ------
 src/subsidy.cpp            | 23 ++++++++++-------------
 src/subsidy_func.h         |  3 ++-
 3 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/core/geometry_type.hpp b/src/core/geometry_type.hpp
index 92a1d97df6..cba944fb6f 100644
--- a/src/core/geometry_type.hpp
+++ b/src/core/geometry_type.hpp
@@ -62,10 +62,4 @@ struct PointDimension {
 	int height;
 };
 
-/** A pair of two integers */
-struct Pair {
-	int a;
-	int b;
-};
-
 #endif /* GEOMETRY_TYPE_HPP */
diff --git a/src/subsidy.cpp b/src/subsidy.cpp
index ff420455d8..2668a62bd7 100644
--- a/src/subsidy.cpp
+++ b/src/subsidy.cpp
@@ -50,14 +50,14 @@ void Subsidy::AwardTo(CompanyID company)
 	char *cn = stredup(company_name);
 
 	/* Add a news item */
-	Pair reftype = SetupSubsidyDecodeParam(this, false);
+	std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(this, false);
 	InjectDParam(1);
 
 	SetDParamStr(0, cn);
 	AddNewsItem(
 		STR_NEWS_SERVICE_SUBSIDY_AWARDED_HALF + _settings_game.difficulty.subsidy_multiplier,
 		NT_SUBSIDIES, NF_NORMAL,
-		(NewsReferenceType)reftype.a, this->src, (NewsReferenceType)reftype.b, this->dst,
+		reftype.first, this->src, reftype.second, this->dst,
 		cn
 	);
 	AI::BroadcastNewEvent(new ScriptEventSubsidyAwarded(this->index));
@@ -72,7 +72,7 @@ void Subsidy::AwardTo(CompanyID company)
  * @param mode Unit of cargo used, \c true means general name, \c false means singular form.
  * @return Reference of the subsidy in the news system.
  */
-Pair SetupSubsidyDecodeParam(const Subsidy *s, bool mode)
+std::pair<NewsReferenceType, NewsReferenceType> SetupSubsidyDecodeParam(const Subsidy *s, bool mode)
 {
 	NewsReferenceType reftype1 = NR_NONE;
 	NewsReferenceType reftype2 = NR_NONE;
@@ -107,10 +107,7 @@ Pair SetupSubsidyDecodeParam(const Subsidy *s, bool mode)
 	}
 	SetDParam(5, s->dst);
 
-	Pair p;
-	p.a = reftype1;
-	p.b = reftype2;
-	return p;
+	return std::pair<NewsReferenceType, NewsReferenceType>(reftype1, reftype2);
 }
 
 /**
@@ -219,8 +216,8 @@ void CreateSubsidy(CargoID cid, SourceType src_type, SourceID src, SourceType ds
 	s->remaining = SUBSIDY_OFFER_MONTHS;
 	s->awarded = INVALID_COMPANY;
 
-	Pair reftype = SetupSubsidyDecodeParam(s, false);
-	AddNewsItem(STR_NEWS_SERVICE_SUBSIDY_OFFERED, NT_SUBSIDIES, NF_NORMAL, (NewsReferenceType)reftype.a, s->src, (NewsReferenceType)reftype.b, s->dst);
+	std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, false);
+	AddNewsItem(STR_NEWS_SERVICE_SUBSIDY_OFFERED, NT_SUBSIDIES, NF_NORMAL, reftype.first, s->src, reftype.second, s->dst);
 	SetPartOfSubsidyFlag(s->src_type, s->src, POS_SRC);
 	SetPartOfSubsidyFlag(s->dst_type, s->dst, POS_DST);
 	AI::BroadcastNewEvent(new ScriptEventSubsidyOffer(s->index));
@@ -494,14 +491,14 @@ void SubsidyMonthlyLoop()
 	for (Subsidy *s : Subsidy::Iterate()) {
 		if (--s->remaining == 0) {
 			if (!s->IsAwarded()) {
-				Pair reftype = SetupSubsidyDecodeParam(s, true);
-				AddNewsItem(STR_NEWS_OFFER_OF_SUBSIDY_EXPIRED, NT_SUBSIDIES, NF_NORMAL, (NewsReferenceType)reftype.a, s->src, (NewsReferenceType)reftype.b, s->dst);
+				std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, true);
+				AddNewsItem(STR_NEWS_OFFER_OF_SUBSIDY_EXPIRED, NT_SUBSIDIES, NF_NORMAL, reftype.first, s->src, reftype.second, s->dst);
 				AI::BroadcastNewEvent(new ScriptEventSubsidyOfferExpired(s->index));
 				Game::NewEvent(new ScriptEventSubsidyOfferExpired(s->index));
 			} else {
 				if (s->awarded == _local_company) {
-					Pair reftype = SetupSubsidyDecodeParam(s, true);
-					AddNewsItem(STR_NEWS_SUBSIDY_WITHDRAWN_SERVICE, NT_SUBSIDIES, NF_NORMAL, (NewsReferenceType)reftype.a, s->src, (NewsReferenceType)reftype.b, s->dst);
+					std::pair<NewsReferenceType, NewsReferenceType> reftype = SetupSubsidyDecodeParam(s, true);
+					AddNewsItem(STR_NEWS_SUBSIDY_WITHDRAWN_SERVICE, NT_SUBSIDIES, NF_NORMAL, reftype.first, s->src, reftype.second, s->dst);
 				}
 				AI::BroadcastNewEvent(new ScriptEventSubsidyExpired(s->index));
 				Game::NewEvent(new ScriptEventSubsidyExpired(s->index));
diff --git a/src/subsidy_func.h b/src/subsidy_func.h
index 4889ead249..cc63577d33 100644
--- a/src/subsidy_func.h
+++ b/src/subsidy_func.h
@@ -14,8 +14,9 @@
 #include "station_type.h"
 #include "company_type.h"
 #include "cargo_type.h"
+#include "news_type.h"
 
-Pair SetupSubsidyDecodeParam(const struct Subsidy *s, bool mode);
+std::pair<NewsReferenceType, NewsReferenceType> SetupSubsidyDecodeParam(const struct Subsidy *s, bool mode);
 void DeleteSubsidyWith(SourceType type, SourceID index);
 bool CheckSubsidised(CargoID cargo_type, CompanyID company, SourceType src_type, SourceID src, const Station *st);
 void RebuildSubsidisedSourceAndDestinationCache();