From 8a1cf03804b9c94bf11a99f2178821618f5a4809 Mon Sep 17 00:00:00 2001
From: Michael Uleysky <uleysky@poi.dvo.ru>
Date: Sun, 30 Jul 2023 17:20:18 +1000
Subject: [PATCH] Improved ReadType-based concepts

---
 include/traits.h | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/include/traits.h b/include/traits.h
index b0d85d7..b85dd5e 100644
--- a/include/traits.h
+++ b/include/traits.h
@@ -3,6 +3,7 @@
 #include <concepts>
 
 class BaseParameters;
+
 using michlib::real;
 
 template<class T>
@@ -82,6 +83,11 @@ template<class D> struct GetReadType_<D, false, true>
  using type = decltype(D().Read(MString(), 0));
 };
 
+template<class D> struct GetReadType_<D, false, false>
+{
+ using type = std::decay_t<D>;
+};
+
 template<class T>
 concept HaveDisable = requires(T t) {
  {
@@ -124,19 +130,39 @@ template<class D> using ReadType = internal::GetReadType_<D, ReadPSupported<D>,
 template<class T>
 concept ReadIsGrid = requires {
  {
-  ReadType<T>().XStep()
+  std::declval<ReadType<T>>().XStep()
  } -> std::convertible_to<real>;
  {
-  ReadType<T>().YStep()
+  std::declval<ReadType<T>>().YStep()
  } -> std::convertible_to<real>;
 };
 
 template<class T>
 concept ReadIs2DGeoRectArray = requires {
  {
-  ReadType<T>().Ix2Lon(0)
+  std::declval<ReadType<T>>().Ix2Lon(0)
+ } -> std::convertible_to<real>;
+ {
+  std::declval<ReadType<T>>().Iy2Lat(0)
+ } -> std::convertible_to<real>;
+};
+
+template<class T>
+concept ReadIs2DGeoArray = requires {
+ {
+  std::declval<ReadType<T>>().Lon(0, 0)
+ } -> std::convertible_to<real>;
+ {
+  std::declval<ReadType<T>>().Lat(0, 0)
+ } -> std::convertible_to<real>;
+};
+
+template<class T>
+concept ReadIs1DGeoArray = requires {
+ {
+  std::declval<ReadType<T>>().Lon(0)
  } -> std::convertible_to<real>;
  {
-  ReadType<T>().Iy2Lat(0)
+  std::declval<ReadType<T>>().Lat(0)
  } -> std::convertible_to<real>;
 };