title: g_hash_table: int64 as key
body: <p>I am using <code>glib</code> <code>g_hash_table</code> to create a hash table, with int64 as key and pointer as value.</p>
  
  <p>I tried this code but it fails:</p>
  
  <pre><code>GHashTable* hash = g_hash_table_new(g_int64_hash, g_int64_equal);
  uint64_t mer_v = 0;
  exist_m = g_hash_table_lookup(hash, mer_v);
  </code></pre>
  
  <p>It reports error:</p>
  
  <pre><code>(gdb) bt
  #0  IA__g_int64_hash (v=0x1d89e81700000) at /build/buildd/glib2.0-2.24.1/glib/gutils.c:3294
  #1  0x00007ff2de966ded in g_hash_table_lookup_node (hash_table=0x13a4050, key=0x1d89e81700000) at /build/buildd/glib2.0-2.24.1/glib/ghash.c:309
  #2  IA__g_hash_table_lookup (hash_table=0x13a4050, key=0x1d89e81700000) at /build/buildd/glib2.0-2.24.1/glib/ghash.c:898
  </code></pre>
  
  <p>I used <code>glib</code> data structure quite often, but never tried hash_table with key int64. Cannot find any help from Google. This tutorial does not have any hits as well: <a href="http://www.ibm.com/developerworks/linux/tutorials/l-glib/section5.html" rel="nofollow">http://www.ibm.com/developerworks/linux/tutorials/l-glib/section5.html</a>. </p>
  
  <p>Please help. Thanks.</p>