juce::Identifier constructor ambiguous call to juce::String::String

Hi !

In my void Processor::parameterChanged(const juce::String& parameterId, float newValue) callback I want to create a juce::Identifier to speed up the comparison to find the right parameter to update (if (id == “drive”) {})

I create the Identifier with juce::Identifier id(parameterId) but I get this compile error with MSVC 19.32 :
2>D:\Dev\AmpModeler\libs\juce\modules\juce_audio_processors\utilities/juce_AudioProcessorParameterWithID.h(51,9): error C2668: ‘juce::String::String’: ambiguous call to overloaded function
2>D:\Dev\AmpModeler\libs\juce\modules\juce_core\text/juce_String.h(148,5): message : could be ‘juce::String::String(juce::StringRef)’
2>D:\Dev\AmpModeler\libs\juce\modules\juce_core\text/juce_String.h(112,5): message : or ‘juce::String::String(juce::CharPointer_UTF8)’
2>D:\Dev\AmpModeler\libs\juce\modules\juce_audio_processors\utilities/juce_AudioProcessorParameterWithID.h(51,9): message : while trying to match the argument list ‘(const _Ty)’

I have tried to explicitly cast to different types and even to char* but I always get that same error even thought I do give a juce::String as argument. How can I make sure that the constructor will not try to implicitly cast to somethign I don’t want or is there a better way to check and update my parameters ?

Thanks in advance

You can’t compare a juce::Identifier to char* - see JUCE: Identifier Class Reference. You can only compare against another juce::Identifier or a juce::StringRef.

Easiest would be to replace

if (id == “drive”)


if (id == juce::Identifier{ "drive" })

Thanks for your reply.
Yes I want to compare to a juce::Identifier, all my parametes identifiers are stored in a std::vectorjuce::Identifier.

My problem is at the creation of the Identifier from the juce::String& parameterId at the beginning of the parameterChanged() function.

I will try what you proposed

I have just compiled the following code successfully on my macOS (Xcode 15.3, CMake).

void PluginProcessor::parameterChanged(const juce::String &parameterID, float newValue) {
    const auto id1 = juce::Identifier(parameterID);
    const auto id_gain1 = juce::Identifier("gain1");
    if (id1 == id_gain1) {
        gain1.setGainDecibels(newValue); // a real-time safe gain dsp

However, I am not sure whether it will speed up the comparison.

Thanks ! I’ll try that.
The tutorial on the ValueTree says it is supposed to speed up as it is not a full string comparison. Identifier are stored in a way that, if you create a new one with an already existing ID, it will point to that already allocated memory. With that, the implementation of the comparison is just checking whether the two juce::Identifiers are pointing to the same adress.

It did the job, thanks a lot !