diesel/macros/
ops.rs

1#[macro_export]
2/// Implements the Rust operator for a given type. If you create a new SQL
3/// function, which returns a type that you'd like to use an operator on, you
4/// should invoke this macro. Unfortunately, Rust disallows us from
5/// automatically implementing `Add` and other traits from `std::ops`, under its
6/// orphan rules.
7macro_rules! operator_allowed {
8    ($tpe:ty, $op:ident, $fn_name:ident) => {
9        impl<Rhs> ::std::ops::$op<Rhs> for $tpe
10        where
11            Rhs: $crate::expression::AsExpression<
12                <<$tpe as $crate::Expression>::SqlType as $crate::sql_types::ops::$op>::Rhs,
13            >,
14        {
15            type Output = $crate::internal::table_macro::ops::$op<Self, Rhs::Expression>;
16
17            fn $fn_name(self, __diesel_internal_rhs: Rhs) -> Self::Output {
18                $crate::internal::table_macro::ops::$op::new(
19                    self,
20                    __diesel_internal_rhs.as_expression(),
21                )
22            }
23        }
24    };
25}
26
27#[macro_export]
28/// Indicates that an expression allows all numeric operators. If you create new
29/// SQL functions that return a numeric type, you should invoke this macro that
30/// type. Unfortunately, Rust disallows us from automatically implementing `Add`
31/// for types which implement `Expression`, under its orphan rules.
32macro_rules! numeric_expr {
33    ($tpe:ty) => {
34        $crate::operator_allowed!($tpe, Add, add);
35        $crate::operator_allowed!($tpe, Sub, sub);
36        $crate::operator_allowed!($tpe, Div, div);
37        $crate::operator_allowed!($tpe, Mul, mul);
38    };
39}
40
41#[macro_export]
42#[doc(hidden)]
43macro_rules! __diesel_generate_ops_impls_if_numeric {
44    ($column_name:ident, Nullable<$($inner:tt)::*>) => { $crate::__diesel_generate_ops_impls_if_numeric!($column_name, $($inner)::*); };
45
46    ($column_name:ident, Unsigned<$($inner:tt)::*>) => { $crate::__diesel_generate_ops_impls_if_numeric!($column_name, $($inner)::*); };
47
48    ($column_name:ident, SmallInt) => { $crate::numeric_expr!($column_name); };
49    ($column_name:ident, Int2) => { $crate::numeric_expr!($column_name); };
50    ($column_name:ident, Smallint) => { $crate::numeric_expr!($column_name); };
51    ($column_name:ident, SmallSerial) => { $crate::numeric_expr!($column_name); };
52
53    ($column_name:ident, Integer) => { $crate::numeric_expr!($column_name); };
54    ($column_name:ident, Int4) => { $crate::numeric_expr!($column_name); };
55    ($column_name:ident, Serial) => { $crate::numeric_expr!($column_name); };
56
57    ($column_name:ident, BigInt) => { $crate::numeric_expr!($column_name); };
58    ($column_name:ident, Int8) => { $crate::numeric_expr!($column_name); };
59    ($column_name:ident, Bigint) => { $crate::numeric_expr!($column_name); };
60    ($column_name:ident, BigSerial) => { $crate::numeric_expr!($column_name); };
61
62    ($column_name:ident, Float) => { $crate::numeric_expr!($column_name); };
63    ($column_name:ident, Float4) => { $crate::numeric_expr!($column_name); };
64
65    ($column_name:ident, Double) => { $crate::numeric_expr!($column_name); };
66    ($column_name:ident, Float8) => { $crate::numeric_expr!($column_name); };
67
68    ($column_name:ident, Numeric) => { $crate::numeric_expr!($column_name); };
69
70    ($column_name:ident, $non_numeric_type:ty) => {};
71}
72
73#[macro_export]
74#[doc(hidden)]
75macro_rules! date_time_expr {
76    ($tpe:ty) => {
77        $crate::operator_allowed!($tpe, Add, add);
78        $crate::operator_allowed!($tpe, Sub, sub);
79    };
80}
81
82#[macro_export]
83#[doc(hidden)]
84macro_rules! __diesel_generate_ops_impls_if_date_time {
85    ($column_name:ident, Nullable<$($inner:tt)::*>) => { $crate::__diesel_generate_ops_impls_if_date_time!($column_name, $($inner)::*); };
86    ($column_name:ident, Time) => { $crate::date_time_expr!($column_name); };
87    ($column_name:ident, Date) => { $crate::date_time_expr!($column_name); };
88    ($column_name:ident, Timestamp) => { $crate::date_time_expr!($column_name); };
89    ($column_name:ident, Timestamptz) => { $crate::date_time_expr!($column_name); };
90    ($column_name:ident, $non_date_time_type:ty) => {};
91}
92
93#[macro_export(local_inner_macros)]
94#[doc(hidden)]
95macro_rules! network_expr {
96    ($tpe:ty) => {
97        operator_allowed!($tpe, Add, add);
98        operator_allowed!($tpe, Sub, sub);
99    };
100}
101
102#[macro_export(local_inner_macros)]
103#[doc(hidden)]
104macro_rules! __diesel_generate_ops_impls_if_network {
105    ($column_name:ident, Nullable<$($inner:tt)::*>) => { __diesel_generate_ops_impls_if_network!($column_name, $($inner)::*); };
106    ($column_name:ident, Cidr) => { network_expr!($column_name); };
107    ($column_name:ident, Inet) => { network_expr!($column_name); };
108    ($column_name:ident, $non_network_type:ty) => {};
109}