STXXL fails at creating a map of strings in long numeric - c++11

Question

With the code that follows, I want to create a map of type std::map. By using a debugger, I got that the exception was raised by stl_pair.h at line 368 (pair& operator=(typename conditional<__and_<is_copy_assignable<_T1>, is_copy_assignable<_T2>>::value, const pair&, const __wrap_nonesuch&>::type __p)), which was invoked by the map scanning of cur (*(cur + 1) = *cur;) in the leaf.h insert function of stxxl. I provide the code I used in the following source code:
#include <stxxl/map>
#include <fstream>
#include <string>
#include <cstdint>
typedef uint_fast64_t LONG_NUMERIC;
std::string random_string( size_t length )
{
auto randchar = []() -> char
{
const char charset[] =
"0123456789"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz";
const size_t max_index = (sizeof(charset) - 1);
return charset[ rand() % max_index ];
};
std::string str(length,0);
std::generate_n( str.begin(), length, randchar );
return str;
}
struct CompareGreater22
{
bool operator () (const std::string& a, const std::string& b) const
{ return a > b; }
static std::string max_value()
{ return std::string(); }
};
int main(int argc, char** argv) {
stxxl::config * cfg = stxxl::config::get_instance();
stxxl::disk_config disk1("/mnt/DEC4763AC47614CD/stxxl.tmp", 100 * 1024 * 1024, "syscall unlink");
disk1.direct = stxxl::disk_config::DIRECT_ON; // force O_DIRECT
// add disk to config
cfg->add_disk(disk1);
// template parameter <KeyType, DataType, CompareType, RawNodeSize, RawLeafSize, PDAllocStrategy (optional)>
typedef stxxl::map<std::string, LONG_NUMERIC, CompareGreater22, DATA_NODE_BLOCK_SIZE, DATA_LEAF_BLOCK_SIZE> map_type3;
// Constructor map(node_cache_size_in_bytes, leaf_cache_size_in_bytes)
map_type3 t((map_type3::node_block_type::raw_size)*3, (map_type3::leaf_block_type::raw_size)*3);
//vertex_conversion_map_type t{(vertex_conversion_map_type::node_block_type::raw_size)*3, (vertex_conversion_map_type::leaf_block_type::raw_size)*3};
for (LONG_NUMERIC i = 0; i< 2000; i++) {
t.insert(std::make_pair(random_string(10), i));
}
}
I also provide the dump result:
[STXXL-MSG] STXXL v1.4.99 (prerelease/Debug) (git 0a80a8c55993948f7f2f6c2c5a51ff45b403045b) + gnu parallel(20170406)
[STXXL-MSG] Disk '/mnt/DEC4763AC47614CD/stxxl.tmp' is allocated, space: 100 MiB, I/O implementation: syscall direct=on queue=0 devid=0 unlink_on_open
*** Error in `/anon/software/path': free(): invalid pointer: 0x000055c0cd7688d0 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x7908b)[0x7fd69ff1108b]
/lib/x86_64-linux-gnu/libc.so.6(+0x82c3a)[0x7fd69ff1ac3a]
/lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7fd69ff1ed2c]
/usr/lib/x86_64-linux-gnu/libstdc++.so.6(_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE9_M_assignERKS4_+0xaf)[0x7fd6a0ad0fcf]
/usr/lib/x86_64-linux-gnu/libstdc++.so.6(_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEaSERKS4_+0x9)[0x7fd6a0ad1339]
/anon/software/path(+0x19bfb)[0x55c0cc841bfb]
/anon/software/path(+0x15699)[0x55c0cc83d699]
/anon/software/path(+0x10dba)[0x55c0cc838dba]
/anon/software/path(+0xf6fc)[0x55c0cc8376fc]
/anon/software/path(+0xd46d)[0x55c0cc83546d]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf1)[0x7fd69feb83f1]
/anon/software/path(+0xd01a)[0x55c0cc83501a]
======= Memory map: ========
55c0cc828000-55c0cc9d8000 r-xp 00000000 08:02 509986 /anon/software/path
55c0ccbd7000-55c0ccbdc000 r--p 001af000 08:02 509986 /anon/software/path
55c0ccbdc000-55c0ccbdd000 rw-p 001b4000 08:02 509986 /anon/software/path
55c0ccbdd000-55c0ccbdf000 rw-p 00000000 00:00 0
55c0cd74a000-55c0cd78c000 rw-p 00000000 00:00 0 [heap]
7fd698000000-7fd698021000 rw-p 00000000 00:00 0
7fd698021000-7fd69c000000 ---p 00000000 00:00 0
7fd69f697000-7fd69f698000 ---p 00000000 00:00 0
7fd69f698000-7fd69fe98000 rw-p 00000000 00:00 0
7fd69fe98000-7fd6a0056000 r-xp 00000000 103:05 795936 /lib/x86_64-linux-gnu/libc-2.24.so
7fd6a0056000-7fd6a0255000 ---p 001be000 103:05 795936 /lib/x86_64-linux-gnu/libc-2.24.so
7fd6a0255000-7fd6a0259000 r--p 001bd000 103:05 795936 /lib/x86_64-linux-gnu/libc-2.24.so
7fd6a0259000-7fd6a025b000 rw-p 001c1000 103:05 795936 /lib/x86_64-linux-gnu/libc-2.24.so
7fd6a025b000-7fd6a025f000 rw-p 00000000 00:00 0
7fd6a025f000-7fd6a0275000 r-xp 00000000 103:05 791133 /lib/x86_64-linux-gnu/libgcc_s.so.1
7fd6a0275000-7fd6a0474000 ---p 00016000 103:05 791133 /lib/x86_64-linux-gnu/libgcc_s.so.1
7fd6a0474000-7fd6a0475000 r--p 00015000 103:05 791133 /lib/x86_64-linux-gnu/libgcc_s.so.1
7fd6a0475000-7fd6a0476000 rw-p 00016000 103:05 791133 /lib/x86_64-linux-gnu/libgcc_s.so.1
7fd6a0476000-7fd6a04a3000 r-xp 00000000 103:05 4335250 /usr/lib/x86_64-linux-gnu/libgomp.so.1.0.0
7fd6a04a3000-7fd6a06a2000 ---p 0002d000 103:05 4335250 /usr/lib/x86_64-linux-gnu/libgomp.so.1.0.0
7fd6a06a2000-7fd6a06a3000 r--p 0002c000 103:05 4335250 /usr/lib/x86_64-linux-gnu/libgomp.so.1.0.0
7fd6a06a3000-7fd6a06a4000 rw-p 0002d000 103:05 4335250 /usr/lib/x86_64-linux-gnu/libgomp.so.1.0.0
7fd6a06a4000-7fd6a07ac000 r-xp 00000000 103:05 795940 /lib/x86_64-linux-gnu/libm-2.24.so
7fd6a07ac000-7fd6a09ab000 ---p 00108000 103:05 795940 /lib/x86_64-linux-gnu/libm-2.24.so
7fd6a09ab000-7fd6a09ac000 r--p 00107000 103:05 795940 /lib/x86_64-linux-gnu/libm-2.24.so
7fd6a09ac000-7fd6a09ad000 rw-p 00108000 103:05 795940 /lib/x86_64-linux-gnu/libm-2.24.so
7fd6a09ad000-7fd6a0b26000 r-xp 00000000 103:05 4335931 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.22
7fd6a0b26000-7fd6a0d25000 ---p 00179000 103:05 4335931 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.22
7fd6a0d25000-7fd6a0d2f000 r--p 00178000 103:05 4335931 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.22
7fd6a0d2f000-7fd6a0d31000 rw-p 00182000 103:05 4335931 /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.22
7fd6a0d31000-7fd6a0d35000 rw-p 00000000 00:00 0
7fd6a0d35000-7fd6a0d4d000 r-xp 00000000 103:05 795951 /lib/x86_64-linux-gnu/libpthread-2.24.so
7fd6a0d4d000-7fd6a0f4d000 ---p 00018000 103:05 795951 /lib/x86_64-linux-gnu/libpthread-2.24.so
7fd6a0f4d000-7fd6a0f4e000 r--p 00018000 103:05 795951 /lib/x86_64-linux-gnu/libpthread-2.24.so
7fd6a0f4e000-7fd6a0f4f000 rw-p 00019000 103:05 795951 /lib/x86_64-linux-gnu/libpthread-2.24.so
7fd6a0f4f000-7fd6a0f53000 rw-p 00000000 00:00 0
7fd6a0f53000-7fd6a0f79000 r-xp 00000000 103:05 795932 /lib/x86_64-linux-gnu/ld-2.24.so
7fd6a114b000-7fd6a1150000 rw-p 00000000 00:00 0
7fd6a1174000-7fd6a1178000 rw-p 00000000 00:00 0
7fd6a1178000-7fd6a1179000 r--p 00025000 103:05 795932 /lib/x86_64-linux-gnu/ld-2.24.so
7fd6a1179000-7fd6a117a000 rw-p 00026000 103:05 795932 /lib/x86_64-linux-gnu/ld-2.24.so
7fd6a117a000-7fd6a117b000 rw-p 00000000 00:00 0
7fff9e622000-7fff9e643000 rw-p 00000000 00:00 0 [stack]
7fff9e714000-7fff9e716000 r--p 00000000 00:00 0 [vvar]
7fff9e716000-7fff9e718000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]

Answer 1

TL;DR: Your KeyType is a std::string and consequently non-pod. The STXXL does not support this.
See section Parameterizing STXXL Containers in the official STXXL FAQ.
See How to use std::string as key in stxxl::map here, where somebody had the same issue. Answers below that question describe possible workarounds.