Re: When to prefer formatValue over formattedWrite?

[Per Nordlöw via Digitalmars-d-learn]

On Tuesday, 19 February 2019 at 11:40:09 UTC, Per Nordlöw wrote:

Is `formatValue` more lightweight to the compiler?


I already posted a very similar question at

https://forum.dlang.org/post/xsovipkjyjyumtyzm...@forum.dlang.org

but in this thread I'm interested in knowing if is there is any 
significant difference in compilation-speed and if formatValue 
and/or formattedWrite needs to allocate using the GC when we are 
writing a array of `char`s or a long, directly to standard 
output. In theory the string could be written directly to stdout 
without an extra memory buffer and the `long` could be formatted 
to a temporarily (stack) allocated array of `char`s before 
written to standard output.

When to prefer formatValue over formattedWrite?

[Per Nordlöw via Digitalmars-d-learn]

Is `formatValue` also preferred over `formattedWrite` when 
writing a single value?



Code example:

import std.array : appender;

auto writer1 = appender!string();
writer1.formattedWrite("%08b", 42);

auto writer2 = appender!string();
auto f = singleSpec("%08b");
writer2.formatValue(42, f);


Is `formatValue` more lightweight to the compiler?