add C++ support

This is so not a good idea but i'll need it for Catch2

include/neo.h

@@ -6,11 +6,19 @@
 #error "Only gcc and clang are supported"
 #endif
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "neo/_error.h"
 #include "neo/_types.h"
 #include "neo/_stddef.h"
 #include "neo/_nalloc.h"
 
+#ifdef __cplusplus
+}; /* extern "C" */
+#endif
+
 /*
  * This file is part of libneo.
  * Copyright (c) 2021 Fefie <owo@fef.moe>.

include/neo/_error.h

@@ -2,6 +2,10 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "neo/_types.h"
 
 /**
@@ -46,19 +50,26 @@ void errput(error *err);
  * by `err` is an actual error, i.e. it has been `yeet`ed to.
  * Resources for the error must be released using `nput`.
  */
-#define catch(err) if ((err) != nil && (err)->_number != 0)
+#define ncatch(err) if ((err) != nil && (err)->_number != 0)
+#ifndef __cplusplus
+#	define catch(err) ncatch(err)
+#endif
 
 /**
  * Get the error number.
  * Must only be used within a catch block and before `errput` is called.
  */
-#define errnum(err) ((err)->_number)
+#define errnum(err) ((err) == nil ? 0 : (err)->_number)
 
 /**
  * Get an optional error message, this may be `nil`
  * Must only be used within a catch block and before `errput` is called.
  */
-#define errmsg(err) ((err)->_message)
+#define errmsg(err) ((err) == nil ? nil : (err)->_message)
+
+#ifdef __cplusplus
+}; /* extern "C" */
+#endif
 
 /*
  * This file is part of libneo.

include/neo/_nalloc.h

@@ -2,6 +2,10 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "neo/_toolchain.h"
 #include "neo/_types.h"
 
@@ -46,6 +50,10 @@ void *nzalloc(usize size, error *err);
 __neo_malloc(nfree, 1)
 void *nrealloc(void *ptr, usize newsize, error *err);
 
+#ifdef __cplusplus
+}; /* extern "C" */
+#endif
+
 /*
  * This file is part of libneo.
  * Copyright (c) 2021 Fefie <owo@fef.moe>.

include/neo/_nref.h

@@ -2,6 +2,10 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "neo/_types.h"
 
 /**
@@ -47,6 +51,10 @@ int _neo_nput(struct _neo_nref *ref);
  */
 #define nput(ptr) (_neo_nput( &(ptr)->__neo_nref ))
 
+#ifdef __cplusplus
+}; /* extern "C" */
+#endif
+
 /*
  * This file is part of libneo.
  * Copyright (c) 2021 Fefie <owo@fef.moe>.

include/neo/_stddef.h

@@ -2,19 +2,23 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "neo/_types.h"
 
 #define nil ((void *)0)
 
-#ifndef true
-#define true ((bool)1)
+#if !defined(__cplusplus) && !defined(true)
+#	define true ((bool)1)
 #endif
-#ifndef false
-#define false ((bool)0)
+#if !defined(__cplusplus) && !defined(false)
+#	define false ((bool)0)
 #endif
 
 #ifndef offsetof
-#define offsetof(type, member) __builtin_offsetof(type, member)
+#	define offsetof(type, member) __builtin_offsetof(type, member)
 #endif
 
 /**
@@ -35,6 +39,10 @@
  */
 #define nlen(thing) ((thing)->__neo_nlen)
 
+#ifdef __cplusplus
+}; /* extern "C" */
+#endif
+
 /*
  * This file is part of libneo.
  * Copyright (c) 2021 Fefie <owo@fef.moe>.

include/neo/_toolchain.h

@@ -18,6 +18,12 @@
 #define __neo_fini(fn) \
 	__neo_section(.fini_array) static void (*__neo_fini_##fn)(void) = fn
 
+#ifdef __cplusplus
+#	define __restrict
+#else
+#	define __restrict restrict
+#endif
+
 /*
  * This file is part of libneo.
  * Copyright (c) 2021 Fefie <owo@fef.moe>.

include/neo/_types.h

@@ -2,6 +2,10 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include "neo/_stddef.h"
 
 typedef __INT8_TYPE__		i8;
@@ -25,20 +29,27 @@ typedef float		f32;
 typedef double		f64;
 typedef long double	f128;
 
-typedef _Bool bool;
-
-#define atomic _Atomic
-#define complex _Complex
+#ifdef __cplusplus
+	/* TODO: This is probably not a good idea */
+	#define __neo_atomic_type volatile int
+#else
+	typedef _Bool bool;
+#	ifdef __STDC_NO_ATOMICS__
+#		error "Atomic types are not implemented"
+#	else
+#		define __neo_atomic_type _Atomic int
+#	endif
+#endif
 
 struct _neo_nref {
 	void (*_destroy)(void *);
 	/** byte offset into the struct this is embedded in */
 	usize _offset;
-	atomic int _count;
+	__neo_atomic_type _count;
 };
 /**
  * A basic reference counter for data structures.
- * Embed this into your data structure as the field `__neo_nref`, initialize
+ * Embed this into your data structure using the `NREF_FIELD` macro, initialize
  * it using `nref_init`, and use `nget` and `nput` to increment/decrement the
  * reference counter.
  */
@@ -61,6 +72,10 @@ struct _neo_error {
 };
 typedef struct _neo_error error;
 
+#ifdef __cplusplus
+}; /* extern "C" */
+#endif
+
 /*
  * This file is part of libneo.
  * Copyright (c) 2021 Fefie <owo@fef.moe>.

include/neo/utf.h

@@ -16,6 +16,11 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "neo/_toolchain.h"
 #include "neo/_types.h"
 
 /**
@@ -28,7 +33,7 @@
  * @returns The number of UTF-8 code points (i.e. number of Unicode characters)
  *	excluding the terminating NUL byte; undefined on error
  */
-usize utf8_check(const char *restrict s, error *err);
+usize utf8_check(const char *__restrict s, error *err);
 
 /**
  * Compute the length of a raw UTF-8 encoded, NUL terminated string.
@@ -40,7 +45,7 @@ usize utf8_check(const char *restrict s, error *err);
  * @returns: String length as in Unicode code points (not bytes),
  *	excluding the terminating NUL byte
  */
-usize utf8_strlen(const char *restrict s);
+usize utf8_strlen(const char *__restrict s);
 
 /**
  * Get the amount of bytes a Unicode character takes up in UTF-8.
@@ -68,7 +73,7 @@ usize utf8_chrsize(nchar c, error *err);
  * @returns The amount of bytes taken up by the character,
  *	which is always between 1 and 4 except on errors
  */
-usize utf8_from_nchr(char *restrict dest, nchar c, error *err);
+usize utf8_from_nchr(char *__restrict dest, nchar c, error *err);
 
 /**
  * Decode a UTF-8 character and store it in `c`.
@@ -86,7 +91,11 @@ usize utf8_from_nchr(char *restrict dest, nchar c, error *err);
  * @returns The amount of bytes the character took up when encoded as UTF-8,
  *	which is always between 1 and 4 except on errors
  */
-usize utf8_to_nchr(nchar *c, const char *restrict utf8chr, error *err);
+usize utf8_to_nchr(nchar *c, const char *__restrict utf8chr, error *err);
+
+#ifdef __cplusplus
+}; /* extern "C" */
+#endif
 
 /*
  * This file is part of libneo.

src/nref.c

@@ -1,23 +1,31 @@
 /** See the end of this file for copyright and license terms. */
 
+#include <stdatomic.h>
+
 #include "neo/_nref.h"
 #include "neo/_types.h"
 
+void _neo_nref_init(struct _neo_nref *ref)
+{
+	atomic_init(&ref->_count, 1);
+}
+
 int _neo_nget(struct _neo_nref *ref)
 {
-	return ++ref->_count;
+	int old = atomic_fetch_add(&ref->_count, 1);
+	return old + 1;
 }
 
 int _neo_nput(struct _neo_nref *ref)
 {
-	int count = --ref->_count;
+	int old = atomic_fetch_sub(&ref->_count, 1);
 
-	if (count == 0) {
+	if (old == 1) {
 		void *container = (void *)ref - ref->_offset;
 		ref->_destroy(container);
 	}
 
-	return count;
+	return old - 1;
 }
 
 /*