Re: [boost] Variadic append for std::string

On 12/29/16 11:54, Olaf van der Spek wrote:

On Thu, Dec 29, 2016 at 1:19 AM, Yakov Galka wrote:

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On Tue, Dec 27, 2016 at 4:47 PM, Olaf van der Spek wrote:

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One frequently needs to append stuff to strings, but the standard way (s += "A" + "B" + to_string(42)) isn't optimal due to temporaries.

Can't we already write it through (((s += "A") += "B") += to_string(42))? This is the time I think that assignment operators, other than =, should have had left associativitiy... pity they don't.

We can, but it's ugly and I'd like to avoid the explicit to_string. It also wouldn't allow the two-pass optimization to calculate the final length before allocation.

I already mentioned in the std-proposals discussion that I don't think formatting should be dealed with by std::string or a function named append(). If formatting is to be involved I'd suggest creating a formatting library, but at that point you should provide clear advantages over the other formatting libraries we have in Boost.