trade that flexibility for increased expressive power. Read about [trait
bounds][traits] to see why and how.
+## Resolving ambiguities
+
+Most of the time when generics are involved, the compiler can infer the
+generic parameters automatically:
+
+```rust
+// v must be a Vec<T> but we don't know what T is yet
+let mut v = Vec::new();
+// v just got a bool value, so T must be bool!
+v.push(true);
+// Debug-print v
+println!("{:?}", v);
+```
+
+Sometimes though, the compiler needs a little help. For example, had we
+omitted the last line, we would get a compile error:
+
+```rust,ignore
+let v = Vec::new();
+// ^^^^^^^^ cannot infer type for `T`
+//
+// note: type annotations or generic parameter binding required
+println!("{:?}", v);
+```
+
+We can solve this using either a type annotation:
+
+```rust
+let v: Vec<bool> = Vec::new();
+println!("{:?}", v);
+```
+
+or by binding the generic parameter `T` via the so-called
+[‘turbofish’][turbofish] `::<>` syntax:
+
+```rust
+let v = Vec::<bool>::new();
+println!("{:?}", v);
+```
+
+The second approach is useful in situations where we don’t want to bind the
+result to a variable. It can also be used to bind generic parameters in
+functions or methods. See [Iterators § Consumers](iterators.html#consumers)
+for an example.
+
[traits]: traits.html
[Vec]: ../std/vec/struct.Vec.html
+[turbofish]: https://doc.rust-lang.org/std/iter/trait.Iterator.html#method.collect
let one_to_one_hundred = (1..101).collect::<Vec<i32>>();
```
-If you remember, the `::<>` syntax allows us to give a type hint,
-and so we tell it that we want a vector of integers. You don't always
-need to use the whole type, though. Using a `_` will let you provide
-a partial hint:
+If you remember, the [`::<>` syntax](generics.html#resolving-ambiguities)
+allows us to give a type hint that tells the compiler we want a vector of
+integers. You don't always need to use the whole type, though. Using a `_`
+will let you provide a partial hint:
```rust
let one_to_one_hundred = (1..101).collect::<Vec<_>>();
<!-- Generics -->
* `path<…>` (*e.g.* `Vec<u8>`): specifies parameters to generic type *in a type*. See [Generics].
-* `path::<…>`, `method::<…>` (*e.g.* `"42".parse::<i32>()`): specifies parameters to generic type, function, or method *in an expression*.
+* `path::<…>`, `method::<…>` (*e.g.* `"42".parse::<i32>()`): specifies parameters to generic type, function, or method *in an expression*. See [Generics § Resolving ambiguities](generics.html#resolving-ambiguities).
* `fn ident<…> …`: define generic function. See [Generics].
* `struct ident<…> …`: define generic structure. See [Generics].
* `enum ident<…> …`: define generic enumeration. See [Generics].