Is there a compilation flag to detect duplicate lamda parameter-lambda member?

Question

This code compiles with g++, no collision is detected, although s is the parameter captured by lambda and the lambda parameter. My compiler is g++.

gcc Version is

gcc (Debian 4.9.2-10+deb8u2) 4.9.2
Copyright (C) 2014 Free Software Foundation, Inc.

and I am using these compilation flags :

-W 
-Wall
-ansi
-pedantic
-s 
-march=native
-flto 
-fwhole-program 
-Wfatal-errors 
-Wextra 
-std=c++1y 
-frename-registers 
-fipa-pta 
-Ofast 
-pedantic-errors 
-fira-loop-pressure
-fomit-frame-pointer
-fforce-addr 
-falign-functions 
-fno-cprop-registers 
-fstrength-reduce

Code is

#include <vector>
#include <algorithm>
#include <iostream>

int main (int argc, char* argv []) {
  int s (0);
  std::vector<int> vec ({3, 5, 13, 1});
  std::for_each (vec.begin (), vec.end (), [&s] (const int& s) {
    s = s>s?s:s;
  });
  std::cout << "max ox v is " << s << std::endl;
}

Is there a compilation option to detect this kind of error ?

You want a compiler flag to pass to the `g++` command, right? — Ryan Zhang, Jun 23 '22 at 12:20
Flagging as not reproducible, because [both g++ and clang refuse this code](https://godbolt.org/z/h3Y7dW1dP) without using special flags. — Enlico, Jun 23 '22 at 12:28
with additionnal includes, (vector, algorithm and iostream) the codes compile on my Linux Debian8 Lenovo Think Center.... and would not like it to ! I am using g++ — Saint-Martin, Jun 23 '22 at 13:00
the use of `tmp` is not needed and just makes the code less clear. Just do `std::vector vec{3, 5, 13, 1};` — bolov, Jun 23 '22 at 15:05

score 0 · Accepted Answer · answered Jun 23 '22 at 15:29

0

Upgrade your compilers.

Based on https://godbolt.org/z/h3Y7dW1dP that warning is missing for gcc 8.5 (with -std=c++17) and clang 7.1.0.

You should upgrade to gcc 9.1 and clang 8.0.0 or later. (Preferably a lot later.)

answered Jun 23 '22 at 15:29

Hans Olsson

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Is there a compilation flag to detect duplicate lamda parameter-lambda member?

1 Answers1