From a1815db9732fc0e8972f925fb6161e0ccb8e6952 Mon Sep 17 00:00:00 2001
From: James-Mart <jmartx93@gmail.com>
Date: Thu, 5 Sep 2024 16:03:34 +0000
Subject: [PATCH 1/2] add some concepts to blob compare to increase readability

---
 .../psibase/common/include/psibase/blob.hpp   | 21 +++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/libraries/psibase/common/include/psibase/blob.hpp b/libraries/psibase/common/include/psibase/blob.hpp
index 7137d61b2..1d977f036 100644
--- a/libraries/psibase/common/include/psibase/blob.hpp
+++ b/libraries/psibase/common/include/psibase/blob.hpp
@@ -4,16 +4,29 @@
 #include <algorithm>
 #include <type_traits>
 
+template <typename T>
+concept IsByteType =
+    std::is_same_v<std::decay_t<T>, char> || std::is_same_v<std::decay_t<T>, unsigned char>;
+
+template <typename T>
+concept IsContainerLike = requires(T t) {
+   {
+      t.data()
+   } -> std::convertible_to<const void*>;
+   {
+      t.size()
+   } -> std::convertible_to<std::size_t>;
+};
+
 namespace psibase
 {
    // Compare vector, string, string_view, shared_string (unsigned)
    template <typename A, typename B>
+      requires IsContainerLike<A> && IsContainerLike<B> &&
+               IsByteType<decltype(*std::declval<A>().data())> &&
+               IsByteType<decltype(*std::declval<B>().data())>
    int compare_blob(const A& a, const B& b)
    {
-      static_assert(std::is_same_v<std::decay_t<decltype(*a.data())>, char> ||
-                    std::is_same_v<std::decay_t<decltype(*a.data())>, unsigned char>);
-      static_assert(std::is_same_v<std::decay_t<decltype(*b.data())>, char> ||
-                    std::is_same_v<std::decay_t<decltype(*b.data())>, unsigned char>);
       auto r = memcmp(a.data(), b.data(), std::min(a.size(), b.size()));
       if (r)
          return r;

From 8903dcc9b6078f7b30b8ab673847355091ae7c76 Mon Sep 17 00:00:00 2001
From: James-Mart <jmartx93@gmail.com>
Date: Tue, 10 Sep 2024 19:35:38 +0000
Subject: [PATCH 2/2] pr feedback - improve blob compare concepts

---
 .../psibase/common/include/psibase/blob.hpp   | 25 +++++++------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/libraries/psibase/common/include/psibase/blob.hpp b/libraries/psibase/common/include/psibase/blob.hpp
index 1d977f036..14afb3042 100644
--- a/libraries/psibase/common/include/psibase/blob.hpp
+++ b/libraries/psibase/common/include/psibase/blob.hpp
@@ -2,37 +2,30 @@
 
 #include <string.h>
 #include <algorithm>
+#include <ranges>
 #include <type_traits>
 
 template <typename T>
-concept IsByteType =
-    std::is_same_v<std::decay_t<T>, char> || std::is_same_v<std::decay_t<T>, unsigned char>;
+concept IsByteType = std::is_same_v<T, char> || std::is_same_v<T, unsigned char>;
 
 template <typename T>
-concept IsContainerLike = requires(T t) {
-   {
-      t.data()
-   } -> std::convertible_to<const void*>;
-   {
-      t.size()
-   } -> std::convertible_to<std::size_t>;
-};
+concept IsByteRange = std::ranges::contiguous_range<T> && std::ranges::sized_range<T> &&
+                      IsByteType<std::remove_cvref_t<std::ranges::range_value_t<T>>>;
 
 namespace psibase
 {
    // Compare vector, string, string_view, shared_string (unsigned)
    template <typename A, typename B>
-      requires IsContainerLike<A> && IsContainerLike<B> &&
-               IsByteType<decltype(*std::declval<A>().data())> &&
-               IsByteType<decltype(*std::declval<B>().data())>
+      requires IsByteRange<A> && IsByteRange<B>
    int compare_blob(const A& a, const B& b)
    {
-      auto r = memcmp(a.data(), b.data(), std::min(a.size(), b.size()));
+      auto r = memcmp(std::ranges::data(a), std::ranges::data(b),
+                      std::min(std::ranges::size(a), std::ranges::size(b)));
       if (r)
          return r;
-      if (a.size() < b.size())
+      if (std::ranges::size(a) < std::ranges::size(b))
          return -1;
-      if (a.size() > b.size())
+      if (std::ranges::size(a) > std::ranges::size(b))
          return 1;
       return 0;
    }