[Bug libstdc++/80290] [6/7 Regression] g++ uses unreasonable amount of memory compiling nested string maps

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80290

--- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> ---
With gcc-6 every extra member of the init-list increases memory usage
dramatically:

 TOTAL     :   0.64             0.17             0.82             126289 kB
 TOTAL     :   0.76             0.23             1.00             147632 kB
 TOTAL     :   0.88             0.26             1.15             168975 kB

but with gcc-5:

 TOTAL        :   0.03             0.01             0.06               8390 kB
 TOTAL        :   0.03             0.01             0.05               8727 kB
 TOTAL        :   0.05             0.02             0.08               9064 kB