X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/54fa3df9560fe739b5fe20ca561749092cef0fd5..a142609c5dc2a7c3df02497235881beaf47088bf:/doc/runtime.tex

diff --git a/doc/runtime.tex b/doc/runtime.tex
index 0a44f91..6a1941d 100644
--- a/doc/runtime.tex
+++ b/doc/runtime.tex
@@ -732,10 +732,42 @@ instance.
 The following macros and functions manage the standard steps along an
 instance's lifecycle.
 
+\subsubsection{Low-level operations}
+The following macros and functions are agnostic with respect to storage
+allocation strategies.  They don't concern themselves with allocation or
+deallocation, and applications are free to use any suitable mechanism.
+
+\begin{describe*}
+    {\dhead[SOD_INIT]{mac}
+       {@<cls> *SOD_INIT(@<cls>, void *@<p>, @<keywords>);}
+     \dhead[sod_init]{fun}
+       {void *sod_init(const SodClass *@<cls>, void *@<p>, \dots);}
+     \dhead[sod_initv]{fun}
+       {void *sod_initv(const SodClass *@<cls>, void *@<p>, va_list @<ap>);}}
+  Imprints and initializes an instance of a class @<cls> in the storage
+  starting at address~@<p>.
+
+  The direct class for the new instance is specified as a class name to
+  @|SOD_INIT|, or a pointer to a class object to the functions.
+
+  Keyword arguments for the initialization message may be provided.  The
+  @|SOD_INIT| macro expects a single preprocessor-time argument which is
+  a use of one of \descref{KWARGS}{mac} or \descref{NO_KWARGS}{mac}; the
+  @|sod_init| function expects the keywords as a variable-length argument
+  tail; and @|sod_initv| expects the keywords to be passed indirectly,
+  through the captured argument-tail cursor @<ap>.
+
+  The return value is an instance pointer for the class @<cls>; the
+  @|SOD_INIT| macro will have converted it to the correct type, so it should
+  probably be used where possible.  In fact, this is guaranteed to be equal
+  to @<p> by the layout rules described in
+  \xref{sec:structures.layout.instance}.
+\end{describe*}
+
 \subsubsection{Automatic storage duration}
 The following macro constructs an instance with automatic storage duration.
 
-\begin{describe}[SOD_DECL]{mac}{SOD_DECL(@<cls>, @<var>);}
+\begin{describe}[SOD_DECL]{mac}{SOD_DECL(@<cls>, @<var>, @<keywords>);}
   Declares and initializes an instance with automatic storage duration.
 
   Given a class name @<cls> and an identifier @<var>, @|SOD_DECL| declares
@@ -744,6 +776,10 @@ The following macro constructs an instance with automatic storage duration.
   up, and slots for which initializers are defined are set to the appropriate
   initial values.
 
+  Keyword arguments for the initialization message may be provided.  The
+  macro expects a single preprocessor-time argument which is a use of one of
+  \descref{KWARGS}{mac} or \descref{NO_KWARGS}{mac}.
+
   The instance has automatic storage duration: pointers to it will become
   invalid when control exits the scope of the declaration.
 \end{describe}