refactor: replace per-type operator==() and operator<=>() with a single generic template

Add a reflection-based operator==() and operator<=>() template pair that
compare bases then members using the MRDOCS_DESCRIBE metadata.

This removes almost all per-type overloads.

Author: gennaroprota

include/mrdocs/Metadata/DocComment/Block/AdmonitionBlock.hpp

@@ -56,13 +56,6 @@ struct AdmonitionBlock final
         : admonish(admonish_)
     {}
 
-    /** Compare admonitions by kind, title, and contents.
-    */
-    auto operator<=>(AdmonitionBlock const&) const = default;
-
-    /** Equality compares the admonition contents.
-    */
-    bool operator==(AdmonitionBlock const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/BlockBase.hpp

@@ -21,13 +21,19 @@
 #include <mrdocs/Dom/LazyObject.hpp>
 #include <mrdocs/Metadata/DocComment/Block/BlockKind.hpp>
 #include <mrdocs/Metadata/DocComment/Inline.hpp>
+#include <mrdocs/Support/CompareReflectedType.hpp>
 #include <mrdocs/Support/Describe.hpp>
 #include <mrdocs/Support/MapReflectedType.hpp>
 #include <algorithm>
 #include <string>
 
 namespace mrdocs::doc {
 
+/// @copydoc mrdocs::operator<=>(T const&, T const&)
+using mrdocs::operator<=>;
+/// @copydoc mrdocs::operator==(T const&, T const&)
+using mrdocs::operator==;
+
 /* Forward declarations
  */
 #define INFO(Type) struct Type##Block;
@@ -49,16 +55,6 @@ struct MRDOCS_DECL Block
     */
     virtual ~Block() = default;
 
-    /** Three-way comparison on the block contents.
-    */
-    auto
-    operator<=>(Block const& other) const = default;
-
-    /** Equality compares the block contents.
-    */
-    bool
-    operator==(Block const& other) const noexcept = default;
-
     /** View this object as a `Block` reference.
     */
     constexpr Block const& asBlock() const noexcept
@@ -146,10 +142,6 @@ struct BlockCommonBase : Block
     static constexpr bool is##Kind() noexcept { return K == BlockKind::Kind; }
 #include <mrdocs/Metadata/DocComment/Block/BlockNodes.inc>
 
-    /** Compare two blocks that share the same `kind_id`.
-    */
-    auto operator<=>(BlockCommonBase const&) const = default;
-
     MRDOCS_DESCRIBE_CLASS(BlockCommonBase, (Block), ())
 
 protected:
@@ -228,15 +220,6 @@ struct MRDOCS_DECL BlockContainer
         return *this;
     }
 
-    /** Order containers lexicographically by their children.
-    */
-    std::strong_ordering
-    operator<=>(BlockContainer const&) const;
-
-    /** Equality compares the stored child blocks.
-    */
-    bool
-    operator==(BlockContainer const&) const = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/BriefBlock.hpp

@@ -58,9 +58,6 @@ struct BriefBlock final
     */
     using InlineContainer::operator=;
 
-    /** Compare briefs by inline content and provenance.
-    */
-    auto operator<=>(BriefBlock const&) const = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/CodeBlock.hpp

@@ -35,12 +35,6 @@ struct CodeBlock final
     /** Construct an empty code block.
     */
     CodeBlock() noexcept = default;
-    /** Compare code blocks by literal and info string.
-    */
-    auto operator<=>(CodeBlock const&) const = default;
-    /** Equality compares literal and info string.
-    */
-    bool operator==(CodeBlock const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/DefinitionListBlock.hpp

@@ -56,29 +56,6 @@ struct DefinitionListBlock final
     */
     std::vector<DefinitionListItem> items;
 
-    /** Order items and their definitions lexicographically.
-    */
-    auto operator<=>(DefinitionListBlock const& other) const {
-        if (auto const cmp = items.size() <=> other.items.size();
-            !std::is_eq(cmp))
-        {
-            return cmp;
-        }
-        for (std::size_t i = 0; i < items.size(); ++i)
-        {
-            if (auto const cmp = items[i] <=> other.items[i];
-                !std::is_eq(cmp))
-            {
-                return cmp;
-            }
-        }
-        return std::strong_ordering::equal;
-    }
-
-    /** Equality compares the contained items.
-    */
-    bool
-    operator==(DefinitionListBlock const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/DefinitionListItem.hpp

@@ -29,13 +29,6 @@ struct DefinitionListItem final
     */
     InlineContainer term;
 
-    /** Compare items by term and definition blocks.
-    */
-    auto operator<=>(DefinitionListItem const&) const = default;
-
-    /** Equality compares term and definitions.
-    */
-    bool operator==(DefinitionListItem const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/FootnoteDefinitionBlock.hpp

@@ -42,12 +42,6 @@ struct FootnoteDefinitionBlock final
     /** Construct an empty footnote definition.
     */
     FootnoteDefinitionBlock() noexcept = default;
-    /** Compare definitions by label and block content.
-    */
-    auto operator<=>(FootnoteDefinitionBlock const&) const = default;
-    /** Equality compares label and block content.
-    */
-    bool operator==(FootnoteDefinitionBlock const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/HeadingBlock.hpp

@@ -50,13 +50,6 @@ struct HeadingBlock final
     */
     using InlineContainer::InlineContainer;
 
-    /** Order headings by level and inline content.
-    */
-    auto operator<=>(HeadingBlock const&) const = default;
-
-    /** Equality compares level and inline content.
-    */
-    bool operator==(HeadingBlock const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/ListBlock.hpp

@@ -83,29 +83,6 @@ struct ListBlock final
     */
     ListKind listKind = ListKind::Unordered;
 
-    /** Order lists by item content and list style.
-    */
-    auto operator<=>(ListBlock const& other) const {
-        if (auto const cmp = items.size() <=> other.items.size();
-            !std::is_eq(cmp))
-        {
-            return cmp;
-        }
-        for (std::size_t i = 0; i < items.size(); ++i)
-        {
-            if (auto const cmp = items[i] <=> other.items[i];
-                !std::is_eq(cmp))
-            {
-                return cmp;
-            }
-        }
-        return std::strong_ordering::equal;
-    }
-
-    /** Equality compares the list style and items.
-    */
-    bool
-    operator==(ListBlock const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(

include/mrdocs/Metadata/DocComment/Block/ListItem.hpp

@@ -25,13 +25,6 @@ namespace mrdocs::doc {
 struct ListItem final
     : BlockContainer
 {
-    /** Order list items by their child blocks.
-    */
-    auto operator<=>(ListItem const&) const = default;
-
-    /** Equality compares contained blocks.
-    */
-    bool operator==(ListItem const&) const noexcept = default;
 };
 
 MRDOCS_DESCRIBE_STRUCT(