c++ - What's the best "type renaming" method? -


if wanted rename std::string type simpler , more naturally looking string, of these 2 methods should use (based on performance , standard)

should rename preprocessed directive

#define string std::string

or type definition

typedef std::string string;

what's performant method? more familiar , recognized community?

just

using std::string;

if want different name, e.g.

using string = std::string;

avoid macros, don't respect scopes , evil™.

for example, proposed macro

#define string std::string

… yields formal undefined behavior if include standard library header, because defines name used standard library.

c++11 §17.6.4.2.2/1 [macro.names]:

” translation unit includes standard library header shall not #define or #undef names declared in standard library header.


-

Popular posts from this blog

Apache NiFi ExecuteScript: Groovy script to replace Json values via a mapping file -

i working apache nifi 0.5.1 on groovy script replace incoming json values ones contained in mapping file. mapping file looks (it simple .txt): header1;header2;header3 a;some text;a2 i have started following: import groovy.json.jsonbuilder import groovy.json.jsonslurper import java.nio.charset.standardcharsets def flowfile = session.get(); if (flowfile == null) { return; } flowfile = session.write(flowfile, { inputstream, outputstream -> def content = """ { "field1": "a" "field2": "a", "field3": "a" }""" def slurped = new jsonslurper().parsetext(content) def builder = new jsonbuilder(slurped) builder.content.field1 = "a" builder.content.field2 = "some text" builder.content.field3 = "a2" outputstream.write(builder.toprettystring().ge...
Read more

node.js - How do I prevent MongoDB replica set from querying the primary? -

read-operations-only: is there way have mongodb replica set, make mongodb instance on box connected to, mongodb gets queried? i have 3 ec2 instances behind aws load balancer. on each ec2 instance runs mongodb, part of replica set. i have express endpoints on nodejs , connect replica set follows mongodb.mongoclient.connect('mongodb://1.1.1.1,2.2.2.2,3.3.3.3.', function (err, db) { if (err) { complete('{}'); } else { i distribute load of queries evenly across 3 instances of mongodb replica set instead of default having queries routed ec2 instance primary mongodb defined, because destroys point of load balancer (which balance load of queries across 3 instances evenly). my understanding when connecting mongodb replica set, primary instance selected unless primary instance down, , therefore purpose of every secondary instance serve backup. in example people call hot,cold,cold. because there 2...
Read more