Add documentation for concepts

doc/modules/ROOT/pages/concepts/ConstBufferSequence.adoc

@@ -9,3 +9,79 @@
 
 
 = ConstBufferSequence
+
+A __ConstBufferSequence__ represents a collection of `const_buffer` s or `mutable_buffer` s.
+
+
+== Related Identifiers
+
+`is_const_buffer_sequence`.
+
+
+== Requirements
+
+* `T` denotes a type meeting the requirements of __ConstBufferSequence__
+* `t` denotes a const value of type `T`
+* `u` denotes an identifier
+
+[cols="1a,1a,3a"]
+|===
+// Headers
+|Expression|Type|Semantics, Pre/Post-conditions
+
+// Row 1, Column 1
+|`T::value_type`
+// Row 1, Column 2
+|`const_buffer` or `mutable_buffer`
+// Row 1, Column 3
+|This type represents a buffer in the sequence.
+
+// Row 2, Column 1
+|`T::const_iterator`
+// Row 2, Column 2
+|
+// Row 2, Column 3
+|This type represents an iterator type that satisfies the requirements of `std::bidirectional_iterator` whose value type is `const_buffer` or `mutable_buffer`.
+
+// Row 3, Column 1
+|`t.begin()`
+// Row 3, Column 2
+|`T::const_iterator`
+// Row 3, Column 3
+|Returns an iterator to the first element of the sequence.
+
+// Row 4, Column 1
+|`t.end()`
+// Row 4, Column 2
+|`T::const_iterator`
+// Row 4, Column 3
+|Returns an iterator to the element following the last element of the sequence.
+
+// Row 5, Column 1
+|`T u(t)`;
+// Row 5, Column 2
+|
+// Row 5, Column 3
+|`T` satisfies the requirements of `std::copyconstructible` and `std::destructible`.
+
+Post-conditions:
+[source,cpp]
+----
+assert(std::ranges::size(t) == std::ranges::size(u));
+
+for (auto elem : std::views::zip(t, u))
+{
+    assert(std::get<0>(elem).data() == std::get<1>(elem).data());
+    assert(std::get<0>(elem).size() == std::get<1>(elem).size());
+}
+----
+
+|===
+
+
+== Models
+
+* `const_buffer_span`
+* `mutable_buffer_span`
+* `const_buffer_pair`
+* `mutable_buffer_pair`

doc/modules/ROOT/pages/concepts/MutableBufferSequence.adoc

@@ -9,3 +9,76 @@
 
 
 = MutableBufferSequence
+
+A __MutableBufferSequence__ represents a collection of `mutable_buffer` s.
+
+
+== Related Identifiers
+
+`is_mutable_buffer_sequence`.
+
+
+== Requirements
+
+* `T` denotes a type meeting the requirements of __MutableBufferSequence__
+* `t` denotes a const value of type `T`
+
+[cols="1a,1a,3a"]
+|===
+// Headers
+|Expression|Type|Semantics, Pre/Post-conditions
+
+// Row 1, Column 1
+|`T::value_type`
+// Row 1, Column 2
+|`mutable_buffer`
+// Row 1, Column 3
+|This type represents a mutable buffer in the sequence.
+
+// Row 2, Column 1
+|`T::const_iterator`
+// Row 2, Column 2
+|
+// Row 2, Column 3
+|This type represents an iterator type that satisfies the requirements of `std::bidirectional_iterator`.
+
+// Row 3, Column 1
+|`t.begin()`
+// Row 3, Column 2
+|`T::const_iterator`
+// Row 3, Column 3
+|Returns an iterator to the first element of the sequence.
+
+// Row 4, Column 1
+|`t.end()`
+// Row 4, Column 2
+|`T::const_iterator`
+// Row 4, Column 3
+|Returns an iterator to the element following the last element of the sequence.
+
+// Row 5, Column 1
+|`T u(t)`;
+// Row 5, Column 2
+|
+// Row 5, Column 3
+|`T` satisfies the requirements of `std::copyconstructible` and `std::destructible`.
+
+Post-conditions:
+[source,cpp]
+----
+assert(std::ranges::size(t) == std::ranges::size(u));
+
+for (auto elem : std::views::zip(t, u))
+{
+    assert(std::get<0>(elem).data() == std::get<1>(elem).data());
+    assert(std::get<0>(elem).size() == std::get<1>(elem).size());
+}
+----
+
+|===
+
+
+== Models
+
+* `mutable_buffer_span`
+* `mutable_buffer_pair`

doc/modules/ROOT/pages/index.adoc

@@ -34,7 +34,7 @@ To use the library as header-only; that is, to eliminate the requirement
 to link a program to a static or dynamic Boost.URL library, simply place
 the following line in *exactly one* source file in your project.
 
-[source, cpp]
+[source,cpp]
 ----
 #include <boost/buffers/src.hpp>
 ----