How can I check if any unit of a type are within X range of another unit?

[Immolation]

In the most efficient way possible

 

[Tar-Quaeron]

Probably (I'm not sure it's the most efficient way):

function IsUnitUnitType takes nothing returns boolean
    return GetUnitTypeId(GetFilterUnit()) == yourunittype
endfunction

function check takes nothing returns boolean
    return FirstOfGroup(GetUnitsInRangeOfLocMatching(yourrealradius, GetUnitLoc(your unit), Condition(function IsUnitUnitType))) != null 
endfunction

I don't know how you can remove leaks though, because you can't remove the location and destroy the group as return is the last thing you can do in a function. So this will leak.

 

[Kajik]

If you want to check diferent unit types:

function nullFilter takes nothing returns boolean
    return true
endfunction

function IsUnitTypeInRangeOfUnit takes unit u, unittype ut, real radius returns boolean
    local group g = CreateGroup()
    // you can also used some global group or recycled group
    local unit tmpUnit
    
    call GroupEnumUnitsInRange(g, GetUnitX(u), GetUnitY(u), radius, Filter(function nullFilter))
    
    loop
        set tmpUnit = FirstOfGroup(g)
        exitwhen (tmpUnit == null) or IsUnitType(tmpUnit, ut)
        call GroupRemoveUnit(g, tmpUnit)
    endloop
    call DestroyGroup(g)
    set g = null
    
    return tmpUnit != null
endfunction

If you want to check specific unit type (more efficient):

globals
    // Have some global group you will never destroy and never assign any unit to it
    group g = CreateGroup()
    boolean tempBool
endglobals

function IsHeroInRangeOfUnit_callback takes nothing returns boolean
    if IsUnitType(GetFilterUnit(), UNIT_TYPE_HERO) then
        set tempBool = true
    endif
    // You never save any unit to your global group
    return false
endfunction

function IsHeroInRangeOfUnit takes unit u, real radius returns boolean
    set tempBool = false
    call GroupEnumUnitsInRange(g, GetUnitX(u), GetUnitY(u), radius, Filter(function IsHeroInRangeOfUnit_callback))
    return tempBool
endfunction

 

[kingkingyyk3]

Group enum and use InUnitInRange.

 

[Immolation]

Thanks, Kajik solutions works perfectly.