It seems that I need to create N amount of garbage by design.

This does not work, the const has already been defined:

```javascript
try {
  new Proxy({},{});
  const ES6_PROXY = true;
} catch(o_O) {
  const ES6_PROXY = false;
}
```

This does not work neither

```javascript
try {
  new Proxy({},{});
  var ES6_PROXY = true;
} catch(o_O) {
  var ES6_PROXY = false;
}
const ES6_PROXY = false;

// var 'ES6_PROXY' has already been declared
```

neither does the following

```javascript
try {
  new Proxy({},{});
  let ES6_PROXY = true;
} catch(o_O) {
  let ES6_PROXY = false;
}

// Illegal let declaration outside extended mode
```

As summary, there is no way to feature detect and define a const in the
same scope, a closure without the possibility to define such constant as
well is mandatory.

```javascript
const ES6_PROXY = function(){
  try {
    new Proxy({},{});
    return true;
  } catch(o_O) {
    return false;
  }
}();
```

This is not such a huge deal, but it does not feel/look right with bigger
amount of features detection and a growing adoption of constants.

Thoughts?

Cheers
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It seems that I need to create N amount of garbage by design.

This does not work, the const has already been defined:

```javascript
try {
  new Proxy({},{});
  const ES6_PROXY = true;
} catch(o_O) {
  const ES6_PROXY = false;
}
```

This does not work neither

```javascript
try {
  new Proxy({},{});
  var ES6_PROXY = true;
} catch(o_O) {
  var ES6_PROXY = false;
}
const ES6_PROXY = false;

// var 'ES6_PROXY' has already been declared
```

neither does the following

```javascript
try {
  new Proxy({},{});
  let ES6_PROXY = true;
} catch(o_O) {
  let ES6_PROXY = false;
}

// Illegal let declaration outside extended mode
```

As summary, there is no way to feature detect and define a const in the
same scope, a closure without the possibility to define such constant as
well is mandatory.

```javascript
const ES6_PROXY = function(){
  try {
    new Proxy({},{});
    return true;
  } catch(o_O) {
    return false;
  }
}();
```

This is not such a huge deal, but it does not feel/look right with bigger
amount of features detection and a growing adoption of constants.

Thoughts?