X-Git-Url: https://git.distorted.org.uk/~mdw/sod/blobdiff_plain/9e91c8e7b5fcdeb6389ac7ccbcd9c77348c4493a..4f634d205ba36abb1a9b0a0d81a2912f1b3ff96a:/lib/keyword.3?ds=inline

diff --git a/lib/keyword.3 b/lib/keyword.3
index 88da56e..db5b86d 100644
--- a/lib/keyword.3
+++ b/lib/keyword.3
@@ -212,6 +212,17 @@ Argument vectors are rather inconvenient to use,
 but are the only practical way in which a caller can decide at runtime
 which arguments to include in a call,
 which is useful when writing wrapper functions.
+.PP
+Perhaps surprisingly,
+keyword arguments have a relatively small performance impact.
+On the author's aging laptop,
+a call to a simple function,
+passing two out of three keyword arguments,
+takes about 30 cycles longer than
+calling a standard function which just takes integer arguments.
+On the other hand,
+quite a lot of code is involved in decoding keyword arguments,
+so code size will naturally suffer.
 .
 .SS Type definitions
 The header file defines two simple structure types.
@@ -817,8 +828,9 @@ storing the results in
 It assumes that the first keyword name
 is in an argument named
 .BR kwfirst_ ,
-as set up by
-.B KWTAIL marker described above.
+as set up by the
+.B KWTAIL
+marker described above.
 .PP
 The macro expands both to a variable declaration and a statement:
 in C89, declarations must precede statements,
@@ -892,7 +904,7 @@ If
 .I set
 is an identifier then
 .IP
-.B "KWPARSE_EMPTY(" set ");"
+.BI "KWPARSE_EMPTY(" set ");"
 .PP
 (note the lack of underscore)
 checks that the enclosing function has been passed