error: the concat operator `~` must be surrounded by spaces
 --> <source attribute>:1:4
       "~b }}"
 --> tests/ui/concat.rs:4:21
  |
4 | #[template(source = r#"{{ a~b }}"#, ext = "txt")]
  |                     ^^^^^^^^^^^^^^

error: the concat operator `~` must be surrounded by spaces
 --> <source attribute>:1:4
       " ~b }}"
  --> tests/ui/concat.rs:11:21
   |
11 | #[template(source = r#"{{ a ~b }}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^^

error: the concat operator `~` must be surrounded by spaces
 --> <source attribute>:1:4
       "~ b }}"
  --> tests/ui/concat.rs:18:21
   |
18 | #[template(source = r#"{{ a~ b }}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^^

error: the concat operator `~` must be surrounded by spaces
 --> <source attribute>:1:4
       "~b~}}"
  --> tests/ui/concat.rs:25:21
   |
25 | #[template(source = r#"{{~a~b~}}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^

error: the concat operator `~` must be surrounded by spaces
 --> <source attribute>:1:4
       " ~b~}}"
  --> tests/ui/concat.rs:32:21
   |
32 | #[template(source = r#"{{~a ~b~}}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^^

error: the concat operator `~` must be surrounded by spaces
 --> <source attribute>:1:4
       "~ b~}}"
  --> tests/ui/concat.rs:39:21
   |
39 | #[template(source = r#"{{~a~ b~}}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^^

error: failed to parse template source
 --> <source attribute>:1:7
       "}}"
  --> tests/ui/concat.rs:46:21
   |
46 | #[template(source = r#"{{ a ~ }}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^

error: failed to parse template source
 --> <source attribute>:1:3
       "~ b }}"
  --> tests/ui/concat.rs:52:21
   |
52 | #[template(source = r#"{{ ~ b }}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^

error: failed to parse template source
 --> <source attribute>:1:6
       "~}}"
  --> tests/ui/concat.rs:58:21
   |
58 | #[template(source = r#"{{~a ~~}}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^

error: failed to parse template source
 --> <source attribute>:1:3
       "~ b~}}"
  --> tests/ui/concat.rs:64:21
   |
64 | #[template(source = r#"{{~~ b~}}"#, ext = "txt")]
   |                     ^^^^^^^^^^^^^^