X-Git-Url: http://www.project-moonshot.org/gitweb/?a=blobdiff_plain;f=doc%2Fapiref.rst;h=ea38343438553278508bdfe4addaf2220af0fc70;hb=234ee4728124d8d07412d159b45dd10854b6d6d8;hp=57b5e3145e31c42f0362e554a8cfa02e32b4fdb2;hpb=fd259ff68c095c613acf952cc63407f294241923;p=jansson.git

diff --git a/doc/apiref.rst b/doc/apiref.rst
index 57b5e31..ea38343 100644
--- a/doc/apiref.rst
+++ b/doc/apiref.rst
@@ -41,6 +41,12 @@ Objects of :ctype:`json_t` are always used through a pointer. There
 are APIs for querying the type, manipulating the reference count, and
 for constructing and manipulating values of different types.
 
+Unless noted otherwise, all API functions return an error value if an
+error occurs. Depending on the function's signature, the error value
+is either *NULL* or -1. Invalid arguments or invalid input are
+apparent sources for errors. Memory allocation and I/O operations may
+also cause errors.
+
 
 Type
 ----
@@ -80,8 +86,8 @@ functions:
 .. cfunction:: int json_typeof(const json_t *json)
 
    Return the type of the JSON value (a :ctype:`json_type` cast to
-   :ctype:`int`). This function is actually implemented as a macro for
-   speed.
+   :ctype:`int`). *json* MUST NOT be *NULL*. This function is actually
+   implemented as a macro for speed.
 
 .. cfunction:: json_is_object(const json_t *json)
                json_is_array(const json_t *json)
@@ -121,7 +127,7 @@ The following functions are used to manipulate the reference count.
 
 .. cfunction:: json_t *json_incref(json_t *json)
 
-   Increment the reference count of *json*.
+   Increment the reference count of *json*. Returns *json*.
 
 .. cfunction:: void json_decref(json_t *json)