Add missing X:: docs

Author: coke

doc/Type/X/Numeric/CannotConvert.rakudoc

@@ -0,0 +1,41 @@
+=begin pod :kind("Type") :subkind("class") :category("exception")
+
+=TITLE class X::Numeric::CannotConvert
+
+=SUBTITLE Error while trying to coerce a number to another type
+
+    class X::Numeric::CannotConvert is Exception { }
+
+Occurs when an attempt to coerce a L<C<Inf>|/type/Num#Inf> or
+a L<C<NaN>|/type/Num#NaN> to a L<C<Numeric>|/type/Numeric> type.
+
+
+For example
+
+    say Inf.Int;
+    CATCH { default { put .^name, ': ', .Str } };
+    # OUTPUT: «X::Numeric::CannotConvert: Cannot convert Inf to Int␤»
+
+Most other conversion errors throw L<C<X::Numeric::Real>|/type/X::Numeric::Real>.
+
+=head1 Methods
+
+=head2 method source
+
+    method source()
+
+Returns the value that failed to coerce.
+
+=head2 method target
+
+    method target()
+
+Returns the type to which the coercion was attempted.
+
+=head2 method reason
+
+    method reason(--> Str:D)
+
+Returns the reason that the conversion failed.
+
+=end pod