Warn about upcoming API changes to certain concepts

CHANGELOG.md

@@ -1,3 +1,9 @@
+Version 142:
+
+* Warn about upcoming API changes to certain concepts
+
+--------------------------------------------------------------------------------
+
 Version 141:
 
 * Tidy up some documentation

doc/qbk/07_concepts/BodyReader.qbk

@@ -29,6 +29,11 @@ representation:
 
 [heading Requirements]
 
+[warning
+    These requirements may undergo non-backward compatible
+    changes in subsequent versions.
+]
+
 In this table:
 
 * `R` denotes a type meeting the requirements of [*BodyReader].

doc/qbk/07_concepts/BodyWriter.qbk

@@ -31,6 +31,11 @@ intended to obtain buffers for these scenarios:
 
 [heading Requirements]
 
+[warning
+    These requirements may undergo non-backward compatible
+    changes in subsequent versions.
+]
+
 In this table:
 
 * `W` denotes a type meeting the requirements of [*BodyWriter].

doc/qbk/07_concepts/Fields.qbk

@@ -22,6 +22,11 @@ be serialized.
 
 [heading Requirements]
 
+[warning
+    These requirements may undergo non-backward compatible
+    changes in subsequent versions.
+]
+
 In this table:
 
 * `F` denotes a type that meets the requirements of [*Fields].

doc/qbk/07_concepts/FieldsWriter.qbk

@@ -20,6 +20,11 @@ calls into it once to retrieve the buffers.
 
 [heading Requirements]
 
+[warning
+    These requirements may undergo non-backward compatible
+    changes in subsequent versions.
+]
+
 In this table:
 
 * `W` denotes a type that meets the requirements of [*FieldsWriter].