nng_msg docs converted to mdbook

We're moving to fewer man pages, with related functions grouped
together in the same man page, and this continues the trend.

11 files changed, 162 insertions, 392 deletions

diff --git a/docs/man/libnng.3.adoc b/docs/man/libnng.3.adoc
index e6a0da4b..e13ddf0b 100644
--- a/docs/man/libnng.3.adoc
+++ b/docs/man/libnng.3.adoc
@@ -98,19 +98,19 @@ user-payload and the header carries protocol specific header information.
 Most applications will only interact with the body.
 
 |===
-|xref:nng_msg_alloc.3.adoc[nng_msg_alloc()]|allocate a message
+// |xref:nng_msg_alloc.3.adoc[nng_msg_alloc()]|allocate a message
 |xref:nng_msg_append.3.adoc[nng_msg_append()]|append to message body
 |xref:nng_msg_body.3.adoc[nng_msg_body()]|return message body
-|xref:nng_msg_capacity.3.adoc[nng_msg_capacity()]|return capacity allocated for message body
+// |xref:nng_msg_capacity.3.adoc[nng_msg_capacity()]|return capacity allocated for message body
 |xref:nng_msg_chop.3.adoc[nng_msg_chop()]|remove data from end of message body
 |xref:nng_msg_clear.3.adoc[nng_msg_clear()]|clear message body
-|xref:nng_msg_dup.3.adoc[nng_msg_dup()]|duplicate a message
-|xref:nng_msg_free.3.adoc[nng_msg_free()]|free a message
+// |xref:nng_msg_dup.3.adoc[nng_msg_dup()]|duplicate a message
+// |xref:nng_msg_free.3.adoc[nng_msg_free()]|free a message
 |xref:nng_msg_get_pipe.3.adoc[nng_msg_get_pipe()]|get pipe for message
 |xref:nng_msg_insert.3.adoc[nng_msg_insert()]|prepend to message body
 |xref:nng_msg_len.3.adoc[nng_msg_len()]|return the message body length
-|xref:nng_msg_realloc.3.adoc[nng_msg_realloc()]|reallocate a message
-|xref:nng_msg_reserve.3.adoc[nng_msg_reserve()]|reserve storage for message body
+// |xref:nng_msg_realloc.3.adoc[nng_msg_realloc()]|reallocate a message
+// |xref:nng_msg_reserve.3.adoc[nng_msg_reserve()]|reserve storage for message body
 |xref:nng_msg_set_pipe.3.adoc[nng_msg_set_pipe()]|set pipe for message
 |xref:nng_msg_trim.3.adoc[nng_msg_trim()]|remove data from start of message body
 |xref:nng_recvmsg.3.adoc[nng_recvmsg()]|receive a message
diff --git a/docs/man/nng_msg.5.adoc b/docs/man/nng_msg.5.adoc
deleted file mode 100644
index 5044cf18..00000000
--- a/docs/man/nng_msg.5.adoc
+++ /dev/null
@@ -1,64 +0,0 @@
-= nng_msg(5)
-//
-// Copyright 2019 Staysail Systems, Inc. <info@staysail.tech>
-// Copyright 2018 Capitar IT Group BV <info@capitar.com>
-//
-// This document is supplied under the terms of the MIT License, a
-// copy of which should be located in the distribution where this
-// file was obtained (LICENSE.txt).  A copy of the license may also be
-// found online at https://opensource.org/licenses/MIT.
-//
-
-== NAME
-
-nng_msg - message
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-typedef struct nng_msg nng_msg;
-----
-
-== DESCRIPTION
-
-An `nng_msg` represents a single ((message)) sent between Scalability Protocols
-peers.
-Messages internally have a ((body)), containing the application supplied
-payload, and a ((header)), containing protocol specific routing and similar
-related information.
-
-TIP: Using message-oriented functions is a good way to reduce the likelihood
-of data copies and improve application performance.
-
-Messages are allocated using the xref:nng_msg_alloc.3.adoc[`nng_msg_alloc()`]
-function, and are deallocated using the xref:nng_msg_free.3.adoc[`nng_msg_free()`]
-function.
-
-In addition there are other functions used to access message contents,
-including adding data to either the beginning or end of the message,
-automatic data conversion, and removing data from the beginning or end.
-These functions are designed to try to avoid copying message contents
-by making use of scratch areas at the beginning and end of the message.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_aio_get_msg.3.adoc[nng_aio_get_msg(3)],
-xref:nng_aio_set_msg.3.adoc[nng_aio_set_msg(3)],
-xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
-xref:nng_msg_body.3.adoc[nng_msg_body(3)],
-xref:nng_msg_dup.3.adoc[nng_msg_dup(3)],
-xref:nng_msg_free.3.adoc[nng_msg_free(3)],
-xref:nng_msg_header.3.adoc[nng_msg_header(3)],
-xref:nng_msg_header_len.3.adoc[nng_msg_header_len(3)],
-xref:nng_msg_len.3.adoc[nng_msg_len(3)],
-xref:nng_msg_capacity.3.adoc[nng_msg_capacity(3)],
-xref:nng_msg_reserve.3.adoc[nng_msg_reserve(3)],
-xref:nng_msg_realloc.3.adoc[nng_msg_realloc(3)],
-xref:nng_recvmsg.3.adoc[nng_recvmsg(3)],
-xref:nng_sendmsg.3.adoc[nng_sendmsg(3)],
-xref:nng_strerror.3.adoc[nng_strerror(3)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_msg_alloc.3.adoc b/docs/man/nng_msg_alloc.3.adoc
deleted file mode 100644
index 2754b67e..00000000
--- a/docs/man/nng_msg_alloc.3.adoc
+++ /dev/null
@@ -1,55 +0,0 @@
-= nng_msg_alloc(3)
-//
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
-// Copyright 2018 Capitar IT Group BV <info@capitar.com>
-//
-// This document is supplied under the terms of the MIT License, a
-// copy of which should be located in the distribution where this
-// file was obtained (LICENSE.txt).  A copy of the license may also be
-// found online at https://opensource.org/licenses/MIT.
-//
-
-== NAME
-
-nng_msg_alloc - allocate a message
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-int nng_msg_alloc(nng_msg **msgp, size_t size);
-----
-
-== DESCRIPTION
-
-The `nng_msg_alloc()` function allocates a new message with body length _size_
-and stores the result in __msgp__.
-Messages allocated with this function contain a body and optionally a header.
-They are used with receive and transmit functions.
-
-== RETURN VALUES
-
-This function returns 0 on success, and non-zero otherwise.
-
-== ERRORS
-
-[horizontal]
-`NNG_ENOMEM`:: Insufficient free memory exists to allocate a message.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_msg_free.3.adoc[nng_msg_free(3)],
-xref:nng_msg_body.3.adoc[nng_msg_body(3)],
-xref:nng_msg_dup.3.adoc[nng_msg_dup(3)],
-xref:nng_msg_header.3.adoc[nng_msg_header(3)],
-xref:nng_msg_header_len.3.adoc[nng_msg_header_len(3)],
-xref:nng_msg_len.3.adoc[nng_msg_len(3)],
-xref:nng_msg_capacity.3.adoc[nng_msg_capacity(3)],
-xref:nng_msg_reserve.3.adoc[nng_msg_reserve(3)],
-xref:nng_msg_realloc.3.adoc[nng_msg_realloc(3)],
-xref:nng_strerror.3.adoc[nng_strerror(3)],
-xref:nng_msg.5.adoc[nng_msg(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_msg_capacity.3.adoc b/docs/man/nng_msg_capacity.3.adoc
deleted file mode 100644
index ffc7f5d3..00000000
--- a/docs/man/nng_msg_capacity.3.adoc
+++ /dev/null
@@ -1,46 +0,0 @@
-= nng_msg_capacity(3)
-//
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
-// Copyright 2018 Capitar IT Group BV <info@capitar.com>
-//
-// This document is supplied under the terms of the MIT License, a
-// copy of which should be located in the distribution where this
-// file was obtained (LICENSE.txt).  A copy of the license may also be
-// found online at https://opensource.org/licenses/MIT.
-//
-
-== NAME
-
-nng_msg_capacity - return message body length
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-size_t nng_msg_capacity(nng_msg *msg);
-----
-
-== DESCRIPTION
-
-The `nng_msg_capacity()` returns the storage allocated for the body of message _msg_.
-The capacity includes the current contents of the message and free space after it.
-The message body may grow to capacity without performing any further allocations.
-
-== RETURN VALUES
-
-Allocated capacity for message body.
-
-== ERRORS
-
-None.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_msg_reserve.3.adoc[nng_msg_reserve(3)],
-xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
-xref:nng_msg_body.3.adoc[nng_msg_body(3)],
-xref:nng_msg.5.adoc[nng_msg(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_msg_dup.3.adoc b/docs/man/nng_msg_dup.3.adoc
deleted file mode 100644
index b985d5bb..00000000
--- a/docs/man/nng_msg_dup.3.adoc
+++ /dev/null
@@ -1,49 +0,0 @@
-= nng_msg_dup(3)
-//
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
-// Copyright 2018 Capitar IT Group BV <info@capitar.com>
-//
-// This document is supplied under the terms of the MIT License, a
-// copy of which should be located in the distribution where this
-// file was obtained (LICENSE.txt).  A copy of the license may also be
-// found online at https://opensource.org/licenses/MIT.
-//
-
-== NAME
-
-nng_msg_dup - duplicate a message
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-int nng_msg_dup(nng_msg **dup, nng_msg_t *orig);
-----
-
-== DESCRIPTION
-
-The `nng_msg_dup()` makes a duplicate of the original message _orig_, and
-saves the result in the location pointed by _dup_.
-The actual message body and header content is copied,
-but the duplicate may contain a
-different amount of unused space than the original message.
-
-== RETURN VALUES
-
-This function returns 0 on success, and non-zero otherwise.
-
-== ERRORS
-
-[horizontal]
-`NNG_ENOMEM`:: Insufficient free memory exists to duplicate a message.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
-xref:nng_msg_free.3.adoc[nng_msg_free(3)],
-xref:nng_strerror.3.adoc[nng_strerror(3)],
-xref:nng_msg.5.adoc[nng_msg(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_msg_free.3.adoc b/docs/man/nng_msg_free.3.adoc
deleted file mode 100644
index 1ee045c0..00000000
--- a/docs/man/nng_msg_free.3.adoc
+++ /dev/null
@@ -1,43 +0,0 @@
-= nng_msg_free(3)
-//
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
-// Copyright 2018 Capitar IT Group BV <info@capitar.com>
-//
-// This document is supplied under the terms of the MIT License, a
-// copy of which should be located in the distribution where this
-// file was obtained (LICENSE.txt).  A copy of the license may also be
-// found online at https://opensource.org/licenses/MIT.
-//
-
-== NAME
-
-nng_msg_free - free a message
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-void nng_msg_free(nng_msg *msg);
-----
-
-== DESCRIPTION
-
-The `nng_msg_free()` function deallocates the message _msg_ entirely.
-
-== RETURN VALUES
-
-None.
-
-== ERRORS
-
-None.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
-xref:nng_msg_realloc.3.adoc[nng_msg_realloc(3)],
-xref:nng_msg.5.adoc[nng_msg(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_msg_realloc.3.adoc b/docs/man/nng_msg_realloc.3.adoc
deleted file mode 100644
index bf407289..00000000
--- a/docs/man/nng_msg_realloc.3.adoc
+++ /dev/null
@@ -1,66 +0,0 @@
-= nng_msg_realloc(3)
-//
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
-// Copyright 2018 Capitar IT Group BV <info@capitar.com>
-//
-// This document is supplied under the terms of the MIT License, a
-// copy of which should be located in the distribution where this
-// file was obtained (LICENSE.txt).  A copy of the license may also be
-// found online at https://opensource.org/licenses/MIT.
-//
-
-== NAME
-
-nng_msg_realloc - reallocate a message
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-int nng_msg_realloc(nng_msg *msg, size_t size);
-----
-
-== DESCRIPTION
-
-The `nng_msg_realloc()` function re-allocates a message so that it has
-a body of length _size_.
-This message attempts to avoid extra allocations,
-and will reuse the existing memory when possible.
-
-TIP: `nng_msg_realloc` is suitable for creating space for direct writing of data.
-When appending many small pieces of data to a message using xref:nng_msg_append.3.adoc[`nng_msg_append()`],
-allocations may be reduced by first using xref:nng_msg_reserve.3.adoc[`nng_msg_reserve()`]
-to create sufficient space.
-In any case, reallocating or appending to a message is guaranteed to succeed if the resulting
-body length is less than xref:nng_msg_capacity.3.adoc[`nng_msg_capacity()`]. 
-
-NOTE: Pointers to message body and header content obtained prior to this
-function must not be in use, as the underlying memory used for the message
-may have changed, particularly if the message size is increasing.
-
-== RETURN VALUES
-
-This function returns 0 on success, and non-zero otherwise.
-
-== ERRORS
-
-[horizontal]
-`NNG_ENOMEM`:: Insufficient free memory exists to reallocate a message.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_msg_reserve.3.adoc[nng_msg_reserve(3)],
-xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
-xref:nng_msg_append.3.adoc[nng_msg_append(3)],
-xref:nng_msg_body.3.adoc[nng_msg_body(3)],
-xref:nng_msg_chop.3.adoc[nng_msg_chop(3)],
-xref:nng_msg_free.3.adoc[nng_msg_free(3)],
-xref:nng_msg_insert.3.adoc[nng_msg_insert(3)],
-xref:nng_msg_len.3.adoc[nng_msg_len(3)],
-xref:nng_msg_trim.3.adoc[nng_msg_trim(3)],
-xref:nng_strerror.3.adoc[nng_strerror(3)],
-xref:nng_msg.5.adoc[nng_msg(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_msg_reserve.3.adoc b/docs/man/nng_msg_reserve.3.adoc
deleted file mode 100644
index 254c1e94..00000000
--- a/docs/man/nng_msg_reserve.3.adoc
+++ /dev/null
@@ -1,63 +0,0 @@
-= nng_msg_reserve(3)
-//
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
-// Copyright 2018 Capitar IT Group BV <info@capitar.com>
-//
-// This document is supplied under the terms of the MIT License, a
-// copy of which should be located in the distribution where this
-// file was obtained (LICENSE.txt).  A copy of the license may also be
-// found online at https://opensource.org/licenses/MIT.
-//
-
-== NAME
-
-nng_msg_reserve - reserve storage for a message
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-int nng_msg_reserve(nng_msg *msg, size_t capacity);
-----
-
-== DESCRIPTION
-
-The `nng_msg_reserve()` function ensures a message has allocated enough storage 
-to accommodate a body of the given length.
-This message attempts to avoid extra allocations,
-and will reuse the existing memory when possible.
-
-TIP: Using this message before xref:nng_msg_append.3.adoc[`nng_msg_append()`]
-will prevent additional memory allocations until the message's length exceeds
-the alotted capacity.
-
-NOTE: Pointers to message body and header content obtained prior to this
-function must not be in use, as the underlying memory used for the message
-may have changed, particularly if the message capacity is increasing.
-
-== RETURN VALUES
-
-This function returns 0 on success, and non-zero otherwise.
-
-== ERRORS
-
-[horizontal]
-`NNG_ENOMEM`:: Insufficient free memory exists to reallocate a message.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_msg_capacity.3.adoc[nng_msg_capacity(3)],
-xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
-xref:nng_msg_append.3.adoc[nng_msg_append(3)],
-xref:nng_msg_body.3.adoc[nng_msg_body(3)],
-xref:nng_msg_chop.3.adoc[nng_msg_chop(3)],
-xref:nng_msg_free.3.adoc[nng_msg_free(3)],
-xref:nng_msg_insert.3.adoc[nng_msg_insert(3)],
-xref:nng_msg_len.3.adoc[nng_msg_len(3)],
-xref:nng_msg_trim.3.adoc[nng_msg_trim(3)],
-xref:nng_strerror.3.adoc[nng_strerror(3)],
-xref:nng_msg.5.adoc[nng_msg(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/ref/SUMMARY.md b/docs/ref/SUMMARY.md
index eb20a8c8..7e9bcc2d 100644
--- a/docs/ref/SUMMARY.md
+++ b/docs/ref/SUMMARY.md
@@ -2,6 +2,10 @@
 
 - [API Reference](./api/index.md)
 
+  - [Messages](./api/msg/index.md)
+
+    - [nng_msg](./api/msg/nng_msg.md)
+
   - [Threading and Synchronization](./api/thr/index.md)
 
     - [nng_cv](./api/thr/nng_cv.md)
diff --git a/docs/ref/api/msg/index.md b/docs/ref/api/msg/index.md
new file mode 100644
index 00000000..18a3f620
--- /dev/null
+++ b/docs/ref/api/msg/index.md
@@ -0,0 +1,5 @@
+# Messages
+
+These interfaces deal with messages, used in the Scalability Protocols.
+
+- [nng_msg](./nng_msg.md) --- message
diff --git a/docs/ref/api/msg/nng_msg.md b/docs/ref/api/msg/nng_msg.md
new file mode 100644
index 00000000..84d6c273
--- /dev/null
+++ b/docs/ref/api/msg/nng_msg.md
@@ -0,0 +1,147 @@
+# nng_msg
+
+## NAME
+
+nng_msg --- message
+
+## SYNOPSIS
+
+```c
+#include <nng/nng.h>
+
+typedef struct nng_msg nng_msg;
+
+int nng_msg_alloc(nng_msg **msgp, size_t size);
+void nng_msg_free(nng_msg *msg);
+int nng_msg_dup(nng_msg **dup, nng_msg *msg);
+int nng_msg_realloc(nng_msg **msgp, size_t size);
+int nng_msg_reserve(nng_msg *msg, size_t capacity);
+size_t nng_msg_capacity(nng_msg *msg);
+```
+
+## DESCRIPTION
+
+An {{i:`nng_msg`}} represents a single {{i:message}} sent between Scalability Protocols peers.
+
+Messages in Scalability Protocols are the fundamental unit of transmission and reception,
+as these protocols are fundamentally message-oriented.
+
+> [!NOTE]
+> The `nng_msg` structure is opaque, and applications should never try to
+> rely on the size of it, nor access internal members directly.
+> This insulates the application from changes in subsequent _NNG_ versions
+> that would affect the binary representation of the `nng_msg` itself.
+
+Messages have a [body][nng_msg_body]{{hi:body}}, containing the application-supplied
+payload, and a [header][nng_msg_header]{{hi:header}}, containing protocol specific routing and similar
+related information.
+
+> [!TIP]
+> Only applications using [raw mode][raw] need to access the message header.
+
+### Creating and Destroying Messages
+
+Messages are allocated using {{i:`nng_msg_alloc`}},
+and are deallocated using {{i:`nng_msg_free`}}.
+
+The `nng_msg_alloc` function takes a _size_ argument, and returns a message
+with a preallocated body of that size in the _msgp_ parameter.
+
+Messages can be deallocated when no longer needed using `nng_msg_free`.
+
+A message may be duplicated using the {{i:`nng_msg_dup`}} function, which can be useful
+when a copy must be saved or modified. The contents of the duplicate message will
+be the same, but the actual pointers may be different, and the amount of reserved
+space may be different as well.
+
+### Message Size and Capacity
+
+The message size may be changed by use of the {{i:`nng_msg_realloc`}} function. This
+function will reallocate the underlying memory for the message referenced by _msgp_,
+preserving contents, to provide the new buffer, and return the new message in _msgp_.
+If the new size is smaller than the original message, it will
+truncate the message, but not perform any allocations.
+If the new message is different, then the original is freed.
+If reallocation fails due to insufficient memory, then the original is left intact.
+
+If message growth is anticipated, the {{i:`nng_msg_reserve`}} function can be used
+to ensure that the buffers underlying the message will be sufficient to hold a message
+of at least _capacity_ bytes. The actual message {{i:capacity}} can be obtained using the
+{{i:`nng_msg_capacity`}}. As long as the new size will not exceeed that capacity,
+any functions that change the message will do so without an allocation, and are guaranteed
+to succeed.
+
+> [!IMPORTANT]
+> Any pointers to message content obtained before a call to `nng_msg_realloc` or
+> `nng_msg_reserve` (or any other function that changes the message size) should be
+> treated as invalid, as the locations pointed to may be deallocated by these functions.
+
+### Performance Considerations
+
+While there are convenience wrappers for sending and receiving arrays of
+bytes, using message objects directly when possible will give better
+performance by reducing data copies and needless allocations.
+
+These functions are designed to try to avoid copying message contents
+by making use of scratch areas at the beginning and end of the message.
+These scratch areas, the "{{i:headroom}}" and "{{i:tailroom}}", are automatically
+included when allocating a message.
+
+Using `nng_msg_reserve` to ensure that adequate buffer space is availabe
+in advance can reduce repeated allocations and data copies when modifying messages.
+
+## RETURN VALUES
+
+The `nng_msg_alloc`, `nng_msg_dup`, `nng_msg_realloc`, and `nng_msg_reserve`
+functions return zero on success, or an error value on failure, typically `NNG_ENOMEM`.
+
+The `nng_msg_capacity` function returns the total body capacity of the message _msg_.
+
+## ERRORS
+
+- `NNG_ENOMEM`: Insufficient free memory exists to perform the operation.
+
+## Examples
+
+### Example 1: Preparing a message for use
+
+```c
+    #include <nng/nng.h>
+
+    nng_msg *m;
+    if (nng_msg_alloc(&m, strlen("content") + 1) != 0) {
+       // handle error
+    }
+    strcpy(nng_msg_body(m), "content");
+```
+
+### Example 2: Preallocating message content
+
+```c
+    if (nng_msg_alloc(&m, 1024) != 0) {
+        // handle error
+    }
+    while ((val64 = next_datum()) != 0) P
+        if (nng_msg_append_u64(m, val64) != 0) {
+            // handle error
+        }
+    }
+```
+
+## SEE ALSO
+
+[nng_aio_get_msg][nng_aio_get_msg],
+[nng_msg_body][nng_msg_body],
+[nng_msg_header][nng_msg_header],
+[nng_msg_set_pipe][nng_msg_set_pipe],
+[nng_recvmsg][nng_recvmsg],
+[nng_sendmsg][nng_sendmsg]
+
+[nng_msg_body]: ./nng_msg_body.md
+[nng_msg_header]: ./nng_msg_header.md
+[nng_msg_set_pipe]: ./nng_msg_set_pipe.md
+[nng_aio_get_msg]: TODO.md
+[nng_aio_set_msg]: TODO.md
+[nng_recvmsg]: TODO.md
+[nng_sendmsg]: TODO.md
+[raw]: TODO.md