On 05/05/2011 10:32 AM, Stewart, Robert wrote:
Jeff Flinn wrote:
Stewart, Robert wrote:
Vicente BOTET wrote:
De : "Vladimir Batov"
"Stewart, Robert" wrote
Maybe to avoid the temptation of pairing up we could simplify (at least from the user perspectives) down to:
1. T convert_cast(S) 2. T convert_cast(S, T, throw_t =nothrow) I don't see why (2) the user could want to throw when is giving a fallback. So the throw_t =nothrow is not needed.
That's the non-DefaultConstructible, no-sentinel use case:
struct example { example(int); };
If one wants an exception to indicate conversion failure, an initial value is needed and the desire for an exception must be noted:
example const e(convert_cast<example>("1", 3, throw_));
Sorry if I'm just being dense, but if the above throws, the default value is never used, so why supply it?
Think about how convert_cast() might be implemented:
[snip] Is conflating the fallback value with the initial value used by a stringstream-based implementation really a good idea?