of an "if", "for", or "switch" statement, and the composite literal
is not enclosed in parentheses, square brackets, or curly braces.
In this rare case, the opening brace of the literal is erroneously parsed
as the one introducing the block of statements. To resolve the ambiguity,
the composite literal must appear within parentheses.
</p>

<pre>
if x == (T{a,b,c}[i]) { … }
if (x == T{a,b,c}[i]) { … }

<pre>
type T[P *C] …
type T[P (C)] …
type T[P *C|Q] …
…
</pre>

<p>
In these rare cases, the type parameter list is indistinguishable from an
expression and the type declaration is parsed as an array type declaration.
To resolve the ambiguity, embed the constraint in an
<a href="#Interface_types">interface</a> or use a trailing comma:
</p>

<pre>
type T[P interface{*C}] …
type T[P *C,] …

it is a distinct program, so there are some differences.
One is in constant evaluation.
Constant expressions in the assembler are parsed using Go's operator
precedence, not the C-like precedence of the original.
Thus <code>3&amp;1&lt;&lt;2</code> is 4, not 0—it parses as <code>(3&amp;1)&lt;&lt;2</code>
not <code>3&amp;(1&lt;&lt;2)</code>.
Also, constants are always evaluated as 64-bit unsigned integers.