@expr: a constant expression.
@Since: 2.20
+<!-- ##### MACRO G_STATIC_ASSERT_EXPR ##### -->
+<para>
+The G_STATIC_ASSERT_EXPR macro lets the programmer check a condition at
+compile time. The condition needs to be compile time computable.
+</para>
+<para>
+Unlike <literal>G_STATIC_ASSERT</literal>, this macro evaluates to an
+expression and, as such, can be used in the middle of other expressions.
+Its value should be ignored. This can be accomplished by placing it as
+the first argument of a comma expression.
+</para>
+<informalexample><programlisting>
+#define ADD_ONE_TO_INT(x) \
+ (G_STATIC_ASSERT_EXPR(sizeof (x) == sizeof (int)), ((x) + 1))
+</programlisting></informalexample>
+
+@expr: a constant expression.
+@Since: 2.30
<!-- ##### MACRO G_GNUC_EXTENSION ##### -->
<para>
#define G_PASTE_ARGS(identifier1,identifier2) identifier1 ## identifier2
#define G_PASTE(identifier1,identifier2) G_PASTE_ARGS (identifier1, identifier2)
#define G_STATIC_ASSERT(expr) typedef struct { char Compile_Time_Assertion[(expr) ? 1 : -1]; } G_PASTE (_GStaticAssert_, __LINE__)
+#define G_STATIC_ASSERT_EXPR(expr) ((void) sizeof (char[(expr) ? 1 : -1]))
/* Provide a string identifying the current code position */
#if defined(__GNUC__) && (__GNUC__ < 3) && !defined(__cplusplus)