public UsingBlock(CompilerContext ctx, Local local)
{
if (ctx == null)
{
throw new ArgumentNullException("ctx");
}
if (local == null)
{
throw new ArgumentNullException("local");
}
Type type = local.Type;
if ((type.IsValueType || type.IsSealed) && !ctx.MapType(typeof(IDisposable)).IsAssignableFrom(type))
{
return;
}
this.local = local;
this.ctx = ctx;
this.label = ctx.BeginTry();
}
/// <summary>
/// Creates a new "using" block (equivalent) around a variable;
/// the variable must exist, and note that (unlike in C#) it is
/// the variables *final* value that gets disposed. If you need
/// *original* disposal, copy your variable first.
///
/// It is the callers responsibility to ensure that the variable's
/// scope fully-encapsulates the "using"; if not, the variable
/// may be re-used (and thus re-assigned) unexpectedly.
/// </summary>
public UsingBlock(CompilerContext ctx, Local local)
{
if (ctx == null) throw new ArgumentNullException("ctx");
if (local == null) throw new ArgumentNullException("local");
Type type = local.Type;
// check if **never** disposable
if ((type.IsValueType || type.IsSealed) &&
!ctx.MapType(typeof(IDisposable)).IsAssignableFrom(type))
{
return; // nothing to do! easiest "using" block ever
// (note that C# wouldn't allow this as a "using" block,
// but we'll be generous and simply not do anything)
}
this.local = local;
this.ctx = ctx;
label = ctx.BeginTry();
}