From 213f1986c6a8ffcc93b0b8c403b3df24548d090f Mon Sep 17 00:00:00 2001
From: Daniel Baston <dbaston@gmail.com>
Date: Sat, 14 Jan 2023 20:33:17 -0500
Subject: [PATCH] CoordinateSequence: Add type-detecting forEach for use with
 auto lambdas

---
 CMakeLists.txt                             |  2 +-
 include/geos/geom/CoordinateSequence.h     | 10 +++++++++
 src/geom/CoordinateSequence.cpp            | 17 +++++++++------
 tests/unit/geom/CoordinateSequenceTest.cpp | 25 ++++++++++++++++++++++
 4 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 59ce56812b..78e775fdfb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -128,7 +128,7 @@ include(CMakeDependentOption)
 
 ## CMake global variables
 option(BUILD_SHARED_LIBS "Build GEOS with shared libraries" ON)
-set(CMAKE_CXX_STANDARD 11 CACHE STRING "C++ standard version to use (default is 11)")
+set(CMAKE_CXX_STANDARD 14 CACHE STRING "C++ standard version to use (default is 11)")
 
 ## GEOS custom variables
 option(BUILD_BENCHMARKS "Build GEOS benchmarks" OFF)
diff --git a/include/geos/geom/CoordinateSequence.h b/include/geos/geom/CoordinateSequence.h
index e9ae11ca74..c7ec952440 100644
--- a/include/geos/geom/CoordinateSequence.h
+++ b/include/geos/geom/CoordinateSequence.h
@@ -629,6 +629,16 @@ class GEOS_DLL CoordinateSequence {
         }
     }
 
+    template<typename F>
+    void forEach(F&& fun) const {
+        switch(getCoordinateType()) {
+            case CoordinateType::XY:    for (const auto& c : items<CoordinateXY>())   { fun(c); } break;
+            case CoordinateType::XYZ:   for (const auto& c : items<Coordinate>())     { fun(c); } break;
+            case CoordinateType::XYM:   for (const auto& c : items<CoordinateXYM>())  { fun(c); } break;
+            case CoordinateType::XYZM:  for (const auto& c : items<CoordinateXYZM>()) { fun(c); } break;
+        }
+    }
+
     template<typename T, typename F>
     void forEach(F&& fun) const
     {
diff --git a/src/geom/CoordinateSequence.cpp b/src/geom/CoordinateSequence.cpp
index 30308e0bca..0ed926e9dd 100644
--- a/src/geom/CoordinateSequence.cpp
+++ b/src/geom/CoordinateSequence.cpp
@@ -566,16 +566,19 @@ std::ostream&
 operator<< (std::ostream& os, const CoordinateSequence& cs)
 {
     os << "(";
-    for(std::size_t i = 0, n = cs.size(); i < n; ++i) {
-        if(i) {
+
+    bool writeComma = false;
+    auto write = [&os, &writeComma](const auto& coord) {
+        if (writeComma) {
             os << ", ";
-        }
-        if (cs.hasZ()) {
-            os << cs.getAt(i);
         } else {
-            os << cs.getAt<CoordinateXY>(i);
+            writeComma = true;
         }
-    }
+
+        os << coord;
+    };
+
+    cs.forEach(write);
     os << ")";
 
     return os;
diff --git a/tests/unit/geom/CoordinateSequenceTest.cpp b/tests/unit/geom/CoordinateSequenceTest.cpp
index 9d4ae05609..45eb425b13 100644
--- a/tests/unit/geom/CoordinateSequenceTest.cpp
+++ b/tests/unit/geom/CoordinateSequenceTest.cpp
@@ -1392,4 +1392,29 @@ void object::test<52>
     }
 }
 
+// Test type-detecting version of forEach
+template<>
+template<>
+void object::test<53>
+()
+{
+    CoordinateSequence dst(0u, true, true);
+
+    CoordinateSequence src1{{Coordinate{1, 2, 3}, Coordinate{4, 5, 6}}};
+    CoordinateSequence src2{{CoordinateXYM{7, 8, 9}, {10, 11, 12}}};
+
+    auto appendToDst = [&dst](auto& coord) {
+        dst.add(coord);
+    };
+
+    src1.forEach(appendToDst);
+    src2.forEach(appendToDst);
+
+    ensure_equals(dst.size(), 4u);
+    ensure_equals_xyzm(dst.getAt<CoordinateXYZM>(0), CoordinateXYZM{1, 2, 3, DoubleNotANumber});
+    ensure_equals_xyzm(dst.getAt<CoordinateXYZM>(1), CoordinateXYZM{4, 5, 6, DoubleNotANumber});
+    ensure_equals_xyzm(dst.getAt<CoordinateXYZM>(2), CoordinateXYZM{7, 8,    DoubleNotANumber, 9});
+    ensure_equals_xyzm(dst.getAt<CoordinateXYZM>(3), CoordinateXYZM{10, 11,  DoubleNotANumber, 12});
+}
+
 } // namespace tut